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Volume 42, 1909
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Art. XIII.—The Vegetation of the Kermadec Islands.

[Read before the Philosophical Institute of Canterbury, 6th October, 1909.]

Contents.

I.

Introduction.

II.

History of Botanical Investigation.

III.

Geology.

IV.

Climate.

V.

Intoduced Animals and Plants.

VI.

The Plant Formations.

1.

Coastal Formations.

(a.)

Rocks.

(b.)

Mariscus Slopes.

(c.)

Ngaio Scrub.

(d.)

Sand Dunes.

(e.)

Gravel Flat.

2.

Inland Edaphic Formations.

(a.)

Rocks and Cliffs.

(b.)

Swamp.

(c.)

Lakes.

3.

Forest Formations.

(a.)

General Remarks.

(b.)

Leading Physiogomic Plants and their Life-forms.

(c.)

Ecology.

(d.)

Physiognomy.

(1.)

Dry Forest.

(2.)

Wet Forest.

4.

Young Formations.

(a.)

Landslip.

(b.)

Tutu Scrub.

(c.)

Pohutukawa Forest.

5.

Introduced Formations.

(a.)

Ageratum Meadow.

(b.)

Buffalo-grass Meadow.

(c.)

Beard-grass Meadow.

VII.

Geographical Distribution.

(a.)

The Species.

(b.)

The Subtropical Islands Province.

(c.)

The Formations.

(d.)

Dispersal.

VIII.

List of Indigenous Pteridophytes and Spermophytes.

IX.

List of Introduced Plants.

X.

Bibliography.

I. Introduction.

In area such as the south-western Pacific, where any one island does not include parts of two biological regions, one might imagine the limits of each region could be easily defined. Yet such is not the case. True, it is generally agreed that the several islands to the south and east of New Zealand—

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Auckland, Campbell, Macquarie, Antipodes, Bounty, Chathams—unquestionably belong to the New Zealand region, as not only do their natural productions closely resemble those of New Zealand, but the geological structure of some suggests the probability of a former land connection with that country. To the north of New Zealand, however, there are three islands or groups of islands possessing floras and faunas as to whose relationships botanists and zoologists are not agreed. I refer to Lord Howe Island, Norfolk Island, and the Kermadecs. Being all of volcanic origin, they bear no geological evidence of having ever been directly connected with any land-mass. Sunday Island is perhaps an exception, as the pumice tuffs on the north coast include some fragments of hornblende-granite.

Picture icon

Botanical Map of Sunday Island.

Lord Howe Island is included under New South Wales in Mr. Bentham's “Flora Australiensis,” and in Baron von Mueller's “Census of Australian Plants” Norfolk as well is included in the Australian region. Professor R. Tate has pointed out (18; p. 205) that the floras of Lord Howe and Norfolk Islands are allied to that of New Zealand; but these islands are not included in the New Zealand area by Mr. Cheeseman in his “Manual of the New Zealand Flora,” though he enumerates the plants of the Kermadecs.

There is as little agreement among zoologists as among botanists respecting the region to which these islands belong. Australian zoologists claim them apparently because they are most easily worked from Sydney, but Dr. A. R. Wallace has shown (19; p. 453) that their faunas are really allied to that of New Zealand; and Messrs. Parker and Haswell (15; p. 596)

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follow Wallace in including them in the New Zealand region. Mr. W. L. Sclater draws the line between Norfolk and Lord Howe Islands.

If the contour of the ocean-floor be taken into account, the three above-mentioned islands fall without the boundaries of the Australian region, for Lord Howe Island is separated form the continent of Australia by an ocean over 4,000 m. deep, but is connected with New Zealand by a submarine ridge less than 1,800m. below the surface; whilst Norfolk Island and the Kermadecs are much nearer to New Zealand than to Australia, and lie on submarine ridges stretching form New Zealand to Polynesia, though deeper than that reaching to Lord Howe Island.

As regards the claim of these islands to be included in the Polynesian region, although some Polynesian species and genera of plants reach their southern limit in one or more of them, the proportion is not large enough to warrant the inclusion of the islands in that biological region.

The New Zealand biological region may be defined as including all those islands in the south-west Pacific Ocean lying between the parallels of 25° and 60° S. lat. and the meridians of 155° E. and 175° W. long. From a consideration of the distribution of the plants in New Zealand, Dr. Cockayne has divided the two main islands and Stewart Island into provinces, each characterized by certain floristic and ecological features (5; p. 313). North of latitude 38° is the northern, south of latitude 42° the southern, while the intermediate parts he calls the central botanical province. The islands to the south of New Zealand form his subantarctic islands botanical province, while the Chathams and Kermadecs each form a separate province. In the section of this paper dealing with geographical distribution I have endeavoured to show that Lord Howe Island, Norfolk Island, and the Kermadecs together form a natural division, for which I propose the name “subtropical islands province.”

Situated as the Kermadecs are, midway between New Zealand and the Tonga Group on the southern boundary of the Polynesian region, their fauna and flora are of interest alike to New Zealand biologists and students of geographical distribution. The geological structure of the islands, too, may indicate the route and date certain Polynesian species of plants entered New Zealand. The present islands do not seem to have acted as stepping-stones for the passage of many plants between Tonga and New Zealand, or vice versa. Hymenophyllum demissum and Ascarina lucida may be examples of migrants in the first direction, while Melicytus ramiflorus has reached Eua either from Norfolk or Sunday Island. The Kermadecs are the most easterly of the three groups of islands which mark the northern limit of the New Zealand region, and, as they lie far from any land whence they could derive their stock of plants and animals, a knowledge of their flora and fauna will be interesting as showing which organisms are capable of crossing wide stretches of ocean. As to the means of making the journey, some remarks are made under the heading “Geographical Distribution.”

It was my intention to confine myself to a description of the plant covering of the Kermadec Group, and an enumeration of the species found therein; but the affinity of the flora to that of Lord Howe and Norfolk Islands appeared to me striking, and not without significance, hence I thought it advisable to preface my account with a statement of what I believe to be the true position of the Kermadec Islands in the New Zealand biological region, which expression in this paper will include Lord Howe

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Island and Norfolk Island. The floras of these two islands will only be mentioned in so far as they are related to that of the Kermadecs.

Before closing this introduction I wish to express my sincere thanks to those who in one way or another made it possible for this paper to be written: firstly, to those who helped the expedition before leaving New Zealand, and especially to Dr. Hilgendorf, M.A. (then President of the Canterbury Philosophical Institute), Dr. Cockayne, Professor C. Chilton, M.A., D.Sc., and Mr. E. R. Waite, F.L.S.; to the Councils of the Otago Institute and Canterbury Philosophical Institute for grants of money to help defray expenses; to the Marine Department for the loan of meteorological instruments; to Lieutenant Sir Ernest Shackleton for the gift of a boat; and, finally, to those who so readily gave assistance while I was writing the paper—to Mr. T. F. Cheeseman, F.L.S., who looked over one of the collections of plants made by me in the Kermadecs and named the specimens; to Mr. J. H. Maiden, of Sydney, who kindly compared some of my specimens with plants from Norfolk Island; to Dr. Cockayne for many valuable suggestions; and to Mr. R. Speight, M.A., B.Sc., who gave advice on geological matters.

II. History of Botanical Investigation.

In 1854 Captain H. M. Denham, in H.M.S. “Herald,” made a survey of Sunday Island and the neighbouring seas (17; p. 14). He arrived on the 2nd and was occupied till the 24th July, during which time he frequently had to move his vessel on account of the rough weather experienced. Messrs. J. Milne and W. MacGillivray, naturalists on board the “Herald,” made a small collection of plants on Sunday Island. This was forwarded by Captain Denham to Sir W. Hooker, and was described by Sir Joseph Hooker in the Journal of the Linnean Society for 1857 (10; p. 125).

The number of species collected was 41, of which 21 were pteridophytes and 20 spermophytes. Four species were described as new—Coprosma petiolata, C. acutifolia, Scævola gracilis, and Ascarina lanceolata.

In the “Handbook of the New Zealand Flora” (1864-66) 40 species of vascular plants are mentioned as occurring in the Kermadecs. Of those recorded in the Journal of the Linnean Society, four are omitted, doubtless unintentionally, while three species are added—namely, Nephrodium molle, Coriaria thymifolia, and Acæna Sanguisorbæ. These must have crept in by accident, for no one is known to have collected plants on Sunday Island between 1854 and 1864. Two of them do not occur in the Kermadecs; the third, however, Dryopteris parasitica (= N. molle), is a common plant on Sunday Island.

In 1887 the New Zealand Government despatched the colonial steamer “Stella” to the Kermadec Islands for the purpose of formally annexing the group to the colony. Captain Fairchild left Russell on the 12th August, and after a stormy passage to and from the islands, anchored under Cape Maria van Diemen on the 27th August. Landings were effected on Sunday, Macauley, and Curtis Islands. Mr. T. F. Cheeseman, Curator of the Auckland Museum, accompanied the expedition, and being interested chiefly in botany, made a large collection of plants on Sunday Island, the result of his investigations being published in vol. xx of the “Transactions of the New Zealand Institute” (1; p. 151). In the catalogue he gives of phanerogamic plants and ferns inhabiting the Kermadecs, 115 are enumerated-

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but in seven cases the species could not be determined. Mr. Cheeseman's conclusions are,—(1) The Kermadec Islands have received their plants from two sources: there have been two opposite streams of colonisation—one, much the larger and more important, from New Zealand; the other, much less conspicuous, from the Polynesian islands. (2.) The nature and composition of the flora, the relationship to those of New Zealand and Polynesia, and the peculiarities generally, are best explained on the supposition that the islands have been slowly stocked with their plants by chance migrations across the ocean.

Since the publication of the above, two other paper dealing with the flora of the Kermadecs have appeared in the “Transactions of the New Zealand Institute” (2 and 7), in which four new species are described. Only one, however, Poa polyphylla, is an addition to the flora, the others being included in Mr. Cheeseman's list.

Mr. Cheeseman in his “Manual of the New Zealand Flora” includes the names of 104 species of plants as occurring in the Kermadec Islands. From the list given in vol. xx of the Transactions he omits one as being introduced (Polypogon monspeliensis), and seven others, the omission of three of which (Mariscus ustulatus, Paspalum scrobiculatum, Dichelachne sciurea) is probably due to an oversight. Diplazium japonicum, and three species (including Poa polyphylla) collected by Miss Shakespear, are added. This brings the number of species recorded to 107, if the three above omissions be included.

Early in 1907 Mr. W. L. Wallace, of Timaru, and myself made arrangements to visit and stay for a year on Sunday Island for the purpose of studying plant and animal life. Subsequently Messrs. T. Iredale, C. E. Warden, and S. R. Oliver joined the expedition. We left Auckland in the New Zealand Government steamer “Hinemoa” on the 28th December, 1907, and landed our provisions, instruments, &c., in Denham Bay on the 31st December. From a camp in Denham Bay and another near Fleetwood Bluff as bases the whole island was explored, while a motor-launch was used to visit the outlying rocks. The “Hinemoa” called again on the 7th November, 1908, but owing to bad weather we were not able to ship our goods until the 11th. We landed on Macauley Island, Curtis Island, and French Rock on the voyage back, and reached Auckland on the 16th November.

The Kermadec Islands were chosen as the object of our investigation on account of their being in certain respects a little-known portion of the New Zealand biological region. Our collections included specimens of rocks, plants, and animals; while meteorological observations were taken daily for a period of nine months. Besides collecting specimens, I paid much attention to the plant formations existing on the islands. Following are some of the results of my investigations.

The number of species of plants added to the flora is fourteen:—

Trichomanes humile, Dichelachne crinita,
Hymenophyllum flabellatum, Heleocharis acuta,
Cyathea kermadecensis, n. sp., Kyllinga brevifolia,
Nephrolepis cordifolia, Carex lucida,
Histiopteris incisa, Juncus eflusus,
Lycopodium volubile, J. pauciflorus,
Danthonia pilosa, Erechthites prenanthoides.
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Two species hitherto incorrectly indentified, owing to the imperfect nature of the specimens, I am now able to name,—

Dryopteris glabella (A. Cunn), C. Chr. =Nephrodium decompositum, Hook. f., Jour. Linn. Soc. (Bot.), vol. i, p. 129 (not of R. Br.): Veronica breviracemosa, R. B. Oliver= V. salicifolia, Cheeseman, Trans. N.Z. Inst., vol. xx, p. 171 (not of Vahl).

Five species are transferred to the list of introduced plants,—

Cordyline terminalis, Ageratum conyzoides,
Geranium molle, Sonchus oleraceus;
Aleurites moluccana,

and three do not occur in the islands,—

Agropyrum scabrum, Coprosma Baueri.
Acæna Sanguisorbœ,

Asplenum Shuttleworthianum is here restored to specific rank; so that the total now stands at 114 species.

III. Geology

The Kermadec Islands, four in number, lie in a line extending from Sunday Island, in S. lat. 29° 15 W. long. 177° 59, about S. 22° W. to French Rock, in S. lat. 31° 24′, W. long. 178° 51′. They are situated on a submerged plateau, part of the submarine ridge connecting New Zealand with Tonga. This plateau, which is surrounded on all sides by water more than 2,700m. in depth, is now probably rising, as the last movement of which there is any evidence was an upheaval of Sunday Island to the extent of about 60 m.

Sunday Island, the largest of the group, is distant about 950 km. from Tongatabu, and 1,000 km. from the North or East Capes of New Zealand. Its greatest length is 10.3 km., and its area 29.25 sq. km.; Moumoukai, the highest point, is 524 m. above sea-level.

Sunday Island is composed chiefly of pumiceous and others tuffs. There are a few lava-streams, but these have little effect upon the vegetation other than forming the substratum for certain of the coastal and inland rock formations. The tuffs, being of a more or less loose nature, suffer severely from the action of sea and atmosphere. The whole island is of a mountainous character, and the surface has been formed by subaerial denudation into a series of narrow spurs separating deep ravines. Towards the coast these spurs usually terminate abruptly in cliffs with a sheer drop to the sea of from 200m. to 300m. The crater occupies a large portion of the island. The rim is low and narrow on the north, the lowest point being only 55m. above sea-level; elsewhere it is high, averaging over 300m. From it there branch off three main ridges: one runs north-west from Expedition Hill to Hutchison Bluff, another south-west from Mount Junction to Smith Bluff, and the third south-east from Moumoukai to the east coast. Level ground occurs in Denham Bay, in the crater, and on Low Flat and the adjoining terraces. There is a swamp in Denham Bay, and three lakes in the crater.

Except for a gravelly beach in Denham Bay, and a-sandy one on the north side of the island, the coast is rocky—sometimes boulder beaches; more often cliff-débris, consisting of large and small angular blocks of lava

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or tuff. Hence the variety of stations afforded for salt-loving plants is limited.

Through the kindness of Captain Bollons I was able to land on all the islands visited on the voyage from Sunday Island to New Zealand. I am therefore able to give some account of the geology and botany of the three islands of the Kermadec Group lying to the south-south-west of Sunday Island.

Macauley Island, distant 109km. from Sunday, is 2 km. long and 3 sq. km.in extent. The highest point, 237 m. above sea-level, is near the western end, and from here the land slopes away gradually to the eastward, terminating everywhere in cliffs which can be scaled at one place only—the Lava Cascade. The island is composed of beds of pumice overlying lava, and covered with some vesicular scoria and àsh, which forms the soil.

Curtis Islands, 35 km. from Macauley, consist of two rocky islets—detached portions of a crater in a state of thermal activity. The total area is about 0.6 sq. km., and the highest point 100m. above sea-level. The crater-floor contains much hot mud and sulphur, while numerous holes filled with boiling water are dotted. about. Apparently the islands are composed of a kind of tuff. In the short time I was there I saw no lava.

French Rock is distant 83km. from Curtis Islands. It is composed entirely of lava rocks, and is about 250 m. in length and 50m. in height.

The geological evidence of the age of the islands is conflicting. As pointed out by Mr. Speight,* the occurrence of fragments of hornblendegranite indicates the presence of a continental area. On the other hand, any land connection with either Tonga or New Zealand must have been very remote, as deep water now entirely surrounds the Kermadec Group. The structure of Sunday Island is that of a tuff cone built up on a base which at the time of the first deposits was submerged. The oldest visible beds, which fortunately contain fossils, are of submarine origin, and do not, I think, date back further than the Pliocene age. The character of the flora, and the small proportion of endemic species of plants, are further evidence of the recent appearance of the present islands above the surface of the sea. That the Kermadec plateau once formed part of a continent extending in a north-and-south direction is probable; but the fragmentary nature of the productions of the group demands that this land should be submerged before the present islands came into existence (see 1; p. 161).

IV. Climate.

The Kermadec Island are situated near the southern edge of a belt of calms and variable winds lying between the south-east trades and the region of westerly winds. This belt moves slightly northward during the southern winter, so that the weather experienced on Sunday Island in 1908 included many westerly gales during the winter months, but for the remainder of the year was changeable, with some settled weather in March and April. Generally speaking, the climate is mild and equable, with many rainy days, considerable precipitation, much wind, especially in the winter months, and a constantly humid atmosphere.

[Footnote] * “Petrological Notes on Rocks from the Kermadec Islands, and some Geological Evidence of a Former Subtropical Pacific Continent.” (See p. 241 of this volume.)

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Neither a drought nor a hurricane was experienced during my stay on Sunday Island, though both are known to occur there. On one occasion, according to Mrs. T. Bell, who has lived on Sunday Island for the past thirty years, no rain fell for a period of five months; while hurricanes have visited the island about nine times since 1878. The effect of a hurricane is to be seen in one place in Denham Bay, where every tree in its path is blown down. In the forest generally a leaning tree here and there, and the prostrate habit of the large trees of Metrosideros villosa on the ridges, are the only signs of the effect of hurricanes. The trees affected are usually leaning in a northerly direction—that is, away from the quarter (south-east) whence the hurricanes are said invariably to blow.

The temperature during the nine months, February to October, 1908, varied between the extreme limits of 8.7° C. on the 4th August and 29.4° C. on the 1st February, though days hotter than this occurred in January before regular observations were taken. A note in my diary shows a maximum reading of 31.7° C. for the 29th January.

The rainfall is distributed fairly evenly throughout the year, and for the nine months totalled 1;716 mm. In cloudy and rainy weather a mist continually hangs about the hilltops, hence the upper portion of the island receives a considerable amount of moisture more than the lower-lying ground. As a consequence, the upper forest of Sunday Island is quite different from the lower, though the one imperceptibly passes over to the other at an altitude of 200m. to 300 m.

Calm days are rare, and the wind often blows with great violence. On the 2nd April no horizontal movement of the air was recorded by the anemometer; on the 9th March the instrument registered 1,087 km.

On 76 out of 274 days covered by the nine months during which readings were taken the air was saturated. The driest day was the 3rd February, when the degree of relative humidity was 51.

The amount of cloudiness (observations taken at 9 a.m.) averaged 0.6 of the visible sky.

I give two tables showing the weather-conditions at Denham Bay, Sunday Island, for 1908. The observations were taken by Mr. C. E. Warden, but I am entirely responsible for the figures as they appear here corrected and tabulated. Table I shows the weather month by month, while Table II shows the duration of each kind of weather.

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Table I.
Month, 1908. Temperature, c0. Rainfall. Wind. Relative Humidity.
Min Max Mean. Mm Days. Km per Day
February 20.3 25.9 23.1 198 16 364 81
March 19.0 25.8 22.4 175 14 354 90
April 16.8 24.2 20.5 287 16 209 95
May 15.6 21.4 18.5 172 21 200 96
June 15.0 20.1 17.6 151 21 275 93
July 13.3 19.4 16.3 170 27 467 97
August 13.3 18.2 15.7 237 19 401 91
September 12.6 19.2 15.9 100 18 256 84
October 14.9 20.9 17.9 226 24 425 89
Means and totals 15.7 21.7 18.7 1,716 176 328 91
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[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Table II
Direction of Wind. Temperature, co Rainfall. Wind Relative Humidity Per Cent.
Min. Max Mean. Mm. Days. Km.per Day. Days.
S.E. 14.4 20.6 17.5 27 14 195 30 87
E. 17.2 23.7 20.4 154 29 249 60 88
N.E. 16.3 21.6 18.9 597 20 372 26 94
N. 15.3 20.7 18.0 304 15 344 19 93
N.W. 16.0 21.3 18.6 411 27 404 30 95
W. 15.0 22.1 18.5 100 43 346 63 93
S.W. 14.7 21.0 17.8 73 17 448 29 88
S. 15.0 20.2 17.6 50 11 356 17 88

V. Introduced Animals and Plants.

The effect of animals and plants introduced intentionally and accidentally through the agency of man is most marked on the vegetation of Sunday and Macauley Islands. It amounts to an alteration of the forest formation on Sunday Island; and the occupation of ground cleared of forest or scrub, by meadow formations on both Sunday and Macauley Islands. During the early part of last century Sunday Island was the headquarters of an extensive whaling industry carried on in the south-western Pacific. In order to afford means of subsistence for possible castaways the whalers liberated goats on Sunday and Macauley Islands, and, to provide the goats with pasture on Macauley Island, burnt the scrub so that grass might grow. The goats increased rapidly in their new home, and did not suffer from the lack of water on the islands, as these animals are satisfied with the moisture taken with the herbage. On Macauley Island they effectually prevented the regrowth of scrub, so that now in all places accessible to them no more vegetation is to be found than a close-cropped beard-grass (Polypogon monspeliensis) meadow.

On Sunday Island, as their numbers increased the goats spread to all parts, and, being expert cliff-climbers, little vegetation was beyond their reach. They wander about through the forest in herds of twenty or more, and eat a wonderful variety of vegetable substances—bark and leaves of trees, seedlings, and ferns—thus thinning the undergrowth considerably.

Certain plants once common have been almost exterminated by them, and are now found only on cliffs and other inaccessible places. Conspicuous examples are Homolanthus polyandrus, Veronica breviracemosa, Asplenium lucidum, and A. Shuttleworthianum.

The seedlings of other species are seldom allowed to grow up, and hence only such plants as begin their existence on Cyathea trunks, and, growing downwards and often strangling their host, take root in the ground, are able to reach maturity. This commonly happens with Nothopanax arboreum, which promises to become very rare or even extinct on Sunday Island; and often with Metrosideros villosa.

Young plants of Cyathea kermadecensis are greedily eaten, and, though mature plants of this magnificent fern are plentiful, young ones are extremely rare.

With Rhopalostylis Baueri a fair number of the seedlings grow up, as goats merely browse on the young palms, which are everywhere abundant.

The bark is stripped from the trunks of Pisonia Brunoniana and Nothopanax arboreum as far as goats can reach. This operation, however, kills

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Homolanthus polyandrus, which plant Mr. Cheeseman in 1887 (1; p. 172) recorded as “not uncommon.” The species is now almost extinct.

In Denham Bay sheep eat down Scævola gracilis, and in its place Stellaria media and Cerastium viscosum have become abundant.

The invasion of a number of European and other plants has not in itself much altered the physiognomy of the plant formations, but where ground has been disturbed introduced plants are quicker than indigenous species in taking possession. Introduced species do not readily spread far into the forest except in such places where the larger plants have deliberately been cleared away, and here three new and distinct formations have been created. These are the meadows described below.

Ageratum conyzoides was introduced thirty years ago, and is now abundant in several parts of the island. Possibly goats have assisted in spreading this species, which is the only introduced plant taking a prominent part in several of the plant associations.

VI. The Plant Formations.

All the plant formations on Sunday and Macauley Islands are more or less modified through the depredations of introduced goats, which have not only directly expunged certain plants from the forest, but in so doing have made openings which have been partly filled by introduced species. Hence in places it is difficult to imagine what the original forest was like, especially as it is known that a handsome tree, Homolanthus polyandrus, now absent, was once abundant in many places. The undergrowth perhaps suffers most from the introduction of goats, which search out particular plants whose elimination changes its appearance; also, by the extermination of Homolanthus polyandrus, and the suppression of young plants of Pisonia Brunoniana, Nothopanax arboreum, and Cyathea kermadecensis, the physiognomy of the forest may be entirely altered.

In the Kermadec Islands climatic conditions favour the growth of forest; all other plant formations except meadow occurring there may be classed as edaphic. The meadow formations owe their existence to the interference of man, and are gradually being superseded by forest; the swamp in Denham Bay, also, appears to be drying up, and forest taking its place.

The plant formations, then, naturally fall into two groups—the climatic, the character of whose vegetation is governed by atmospheric precipitations, and the edaphic, whose vegetation is chiefly determined by the nature of the soil (16; p. 161). In this paper the plant formations of the Kermadecs are arranged according to their possible evolution, and are divided for purposes of description into five groups—(1) coastal, (2) inland edaphic, (3) forest, (4) young, (5) introduced. The climatic formations are included in the third group, while groups (1) and (2) are edaphic. The last two groups may be termed unstable formations.

Supposing we go back to early Pliocene times, when the Kermadecs were just appearing above the sea-surface, and try to imagine what the conditions would be. The first plants to gain a footing on the new land would be those able to stand wetting with sea-water, such as are now found among coastal rocks.* Thus the coastal formations would be the first

[Footnote] * On Krakatoa the first plants to appear after the destruction of the vegetation in 1883 were chiefly ferns (Treub., quoted by Schimper, 16; p. 185), but the island which remained after the eruption was of some considerable area.

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to appear on small oceanic islands, and the order would be the vegetation of rocks, scrub, sand dunes. Examples of islands in this stage are French Rock and Curtis Island. Next, as the land increased in area there would be more ground beyond the reach of salt spray, and stations for land-plants would appear, the order being rocks, perhaps swamp and lake, and finally forest. The destruction of areas of forest by volcanic eruptions or landshlips would create new ground where the process of colonising would begin anew, but under entirely different conditions, as the devastated area would be surrounded by forest, which would only be hindered from spreading by the barren nature of the soil; and a new factor so far as the formations here described are concerned is the presence of species of introduced plants and animals. On Sunday Island we are able to watch this actually going on, there being two such areas in process of being reforested. One was caused by a large landslip about four years ago, the other by a volcanic outburst in 1872.

The last period in the history of the plant formations began with the advent of man. Hardy cosmopolitan plants were introduced, the original formations cleared, and the ground immediately occupied by the new-comers.

1. Coastal Formations.

Only such formations as can be called “coastal” in the narrowest sense of the term are included in this section. Coastal conditions (see 5; p. 316) depend upon the distance sea-spray may be carried inland regularly and in large quantities by air-currents, which along the shore almost invariably blow towards the land. For instance, in Denham Bay, which is on the west side of Sunday Island, easterly winds coming over the top of the high cliffs have the effect of causing an inrush of air along the beach to compensate for the withdrawal of air from near the cliff-face. Other factors making coastal conditions are salt in the soil, and the little water-holding capacity of the substratum, which in the Kermadecs is rocks, sand, or pumice.

(a.) Rocks.—Under this heading I will include the vegetation of rocky shores and shingle beaches. All the coast-lines of the Kermadec Islands, with the exception of Denham Bay and Low Flat beaches on Sunday Island, are rocky, and differ but little in their vegetation. As in the winter months gales are frequent, the vegetation is often drenched with salt water, while during hurricanes the waves break over a considerable tract of land all round the coasts. The smallest quantity of soil on a ledge or in a crevice seems sufficient to support vegetation, which must rely for its existence chiefly on the abundant rainfall, which, besides supplying moisture, washes down earth from the cliffs above. Plants of Asplenium obtusatum were noticed on the roofs of caves, in which position they depend entirely on the percolation of rain-water carrying sediment through rock-crevices.

The principal plants composing the coastal rock vegetation are Mesembryanthemum australe, Asplenium obtusatum, Poa polyphylla, Coprosma petiolata, Samolus repens stricta, Lobelia anceps, Tetragonia expansa, Apium prostratum, Mariscus ustulatus, Parietaria debilis, and Scirpus nodosus.

Coprosma petiolata occurs as a low prostrate shrub closely hugging the cliff. On Dayrell Islet, where the vegetation is much exposed, the plants are stunted and about I m. high, with exceedingly dense foliage of small rolled leaves. On Fleetwood Bluff the leaf-blades of a male plant measured 53 × 24 mm., 54 × 26mm., 51 × 28mm., were shining, light green, cori-

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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Vegetation of the Kermadec Islands.—Oliver.

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aceous, with the margins recurved or more or less rolled. Leaves of young shoot, 70 × 34 mm., 73 × 34 mm. In exposed places on the east coast of Sunday Island the leaves were usually much rolled, the two parts of the upper surface sometimes touching underneath.

Poa polyphylla forms small tussocks of fine, drooping foliage, with abundant small, moderately dense, drooping panicles projecting beyond the foliage. Leaves narrow, –20 cm. long, 1.5–2 mm. broad, coriaceous, scabrid on the margins and keel. Culm crowded, length to end of panicle ± 35 cm.

Samolus repens stricta is a small subshrub with usually few erect branching stems –30 cm. high, bearing near their extremities small axillary white or pinkish flowers. Leaves small, 10 mm. long, 3 mm. broad, coriaceous, obovate, ending in small points.

Where a lava cliff forms the coast-line, as at the north end of Denham Bay, the plants occur in crevices or on ledges of the cliff-face. In such situations are found Asplenium obtusatum, Samolus repens stricta, Mesembryanthemum australe, Poa polyphylla, Coprosma petiolata, and Lobelia anceps.

On the north coast of Sunday Island, where the cliffs are of a loose material, and fragments are continually falling, a heap of rocks and rubble is formed at the foot. Here occur Asplenium obtusatum, Mesembryanthemum australe, Lobelia anceps, and Samolus repens stricta; while at Rayner Point Parietaria debilis, Apium prostratum, Tetragonia expansa, Rhagodia nutans, and Mesembryanthemum australe are most abundant, with a few plants of Calystegia Soldanella and Mariscus ustulatus. On slopes of tuff at the base of Fleetwood Bluff and the Terraces Scœvola gracilis, Ipomœa pes caprœ, and Imperata Cheesemani occur, also Coprosma petiolata and small prostrate shrubs of Myoporum lœtum.

The coastal rocks on Meyer Island are particularly bare and exposed. Two or three species of lichen are abundant, and in crevices and lodgmentplaces for small quantities of soil the following plants are found: Mesembryanthemum australe, Scirpus nodosus, Asplenium obtusatum, Coprosma petiolata, Mariscus ustulatus, Tetragonia expansa.

Napier Islet is a mere rock rising 60 m. above sea-level. Here and there a crevice contains a little soil, and a few ledges on the western slope support some stunted straggling trees of Metrosideros villosa and Myoporum lœtum. All these little patches of ground are being continually overturned by burrowing shearwaters and petrels, and consequently are for the most part bare. The winter mutton-bird (Œstrelata neglecta) also occupies a portion of the available surface for its nesting-ground. The plants collected were Canavalia obtusifolia, Asplenium obtusatum, Mesembryanthemum australe, Sonchus oleraceus, Rhagodia nutans, Lobelia anceps, Solanum nigrum, Cotula australis, Panicum sanguinale microbachne, and Erigeron canadense.

On Dayrell Islet Mariscus ustulatus, Asplenium obtusatum, Mesembryanthemum australe, Samolus repens stricta, Rhagodia nutans, Tetragonia expansa, and a few others occur.

The nearest land to French Rock is Curtis Island, distant 83 km. I therefore considered myself extremely fortunate in being able to land on this rock, the most southern member of the Kermadec Group, for half an hour (14th November, 1908) during the voyage back from Sunday Island. It is a mere rock, exposed in all its parts to the winds carrying salt spray, while during a hurricane the waves probably dash right over it. Mesembryanthemum australe was abundant near the summit, forming large green patches visible from the ship at some distance, while Asplenium obtusatum

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was also fairly common. Three other species were collected—Senecio lautus, a much-branched, erect, glabrous herb 25 cm. tall, with lanceolate, fleshy, lobed leaves, and rather dense many-flowered corymbs; Deyeuxia Forsteri littoralis, a stunted form with small short panicles; and Parietaria debilis.

(b.) Mariscus Slopes.—Talus slopes at the foot of sea-cliffs, and other steep slopes along the coasts, are usually covered with close-growing tussocks of Mariscus ustulatus, among which other plants occur in greater or lesser numbers. Next in importance to Mariscus ustulatus are Carex Forsteri insularis, Pteris comans, Hypolepis tenuifolia, Scirpus nodosus, and shrubby forms of Myoporum lœtum.

Carex Forsteri insularis forms small tussocks, ½-1 m. high, with crowded, drooping leaves, and many semi-erect slender culms bearing numerous compound spikelets, the upper ones sessile, approximate, the lower on long erect peduncles. Leaves 1 m. long, 1 cm. broad, yellowish-green, coriaceous, margins and keel scabrid.

Talus slopes are composed of débris weathered off the cliff-face. The soil is thus of a loose moving nature, and, having a large proportion of stones, is not touched by burrowing birds. Other coastal slopes, however, having no cliff above them, and hence with a more stable soil, composed of the weathered surface of volcanic tuffs, are used by burrowing petrels and shearwaters for breeding-grounds during the summer months. The soil is thus everywhere being turned over for many months of the year, and in this respect resembles the moving soil of the talus slopes. Hence a similar type of vegetation is found in both stations. Mariscus ustulatus, whose large tussocks cannot be easily rooted up by the birds, is the principal plant, and in many places the sole occupier, of these slopes.

Talus slopes in Denham Bay support a dense covering of vegetation ± 1 m. high, composed chiefly of Mariscus ustulatus, Ageratum conyzoides, Pteris comans, Carex Forsteri insularis, and Sicyos australis. Scirpus nodosus grows in tufts along the base of the slopes just above the reach of the waves.

The steep slopes of Titi Knob, where not covered by forest, form the breeding-ground of large colonies of black-burrowers (Puffinus chlororhynchus) and short-billed titi (Œstrelata nigripennis). The whole surface not occupied by rock is disturbed every year by these two species of sea-birds. Yet it is densely covered with large tussocks of Mariscus ustulatus, with only here and there, except on rocky ground and cliffs, a few plants of Hypolepis tenuifolia, Pteris comans, Carex Forsteri insularis, Myoporum lœtum, and perhaps some others.

The vegetation of Curtis Island is best described under the present heading. The inner slopes and top of the crater-ridge are covered either with Mariscus ustulatus or Mesembryanthemum australe, the two plants generally keeping separate, and each occupying a large share of the surface. Large numbers of sea-birds breed on the island. Black-burrowers and shortbilled titi burrow wherever the soil is loose enough for them to move, while the masked gannet (Sula cyanops) lays on the surface, trampling down the Mesembryanthemum about its nest. When the birds leave at the end of the breeding season the vegetation profits by the amount of guano mixed with the soil, hence a rank growth covers the ground wherever the birds are able to breed. Not uncommon among the Mariscus tussocks on the erater-ridge were plants of Lepidium oleraceum frondosum. This plant occurred in the form of much-branched, rounded bushes, ½ m. or more

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high, with the periphery of dense foliage and numerous clusters of racemes of many small white flowers. Leaves 6–8 cm. long, rhomboid-oblong, the distal half deeply serrate. Other plants noticed on the slopes were Scirpus nodosus, Rhagodia nutans, Parietaria debilis, Deyeuxia Forsteri, Solanum nigrum (pubescent form), and Sonchus oleraceus.

(c.) Ngaio (Myoporum) Scrub.—Next to forest this is perhaps the most important plant association in the Kermadecs. It is essentially coastal, occupying a belt above high-water mark, from which Metrosideros villosa is absent. It is well developed where there is a space between the cliffs and the water's edge, as on the east coast of Sunday Island. It is found at a height of 25 m. above sea-level on the Terraces, and forms most of the vegetation of Meyer Island (highest point, 100 m. above sea-level). The original vegetation of Macauley Island was in all probability nagaio scrub, but no trace of it now remains, it having been burnt by whalers during last century, when goats were liberated for the benefit of castaways. The narrative of the discovery of the island by Captain Sever, in 1788, says, “The top of the land was covered with a coarse kind of grass, and the place affords great plenty of the wild mangrove.” The coarse grass is probably Mariscus ustulatus, and the wild mangrove Myoporum lœtum. In 1887 Mr. Percy Smith observed the charred stumps of some ngaio (Myoporum lœtum), as well as a few living shrubs of the same plant (17; p. 26).

The principal members of the ngaio scrub are Myoporum lœtum, Pteris comans, Macropiper excelsum major, Sicyos australis, Mariscus ustulatus, Carex Forsteri insularis, and Canavalia obtusifolia.

Myoporum lœtum in the scrub formation is a low, spreading, irregularly branched shrub, with the trunk and branches often more or less horizontal. Foliage usually dense, with the upper surface, through which project numerous dead twigs, sloping towards the sea. Leaves –14.5 cm. long,3-4.5 cm. broad, light green, thick, almost fleshy, often deeply serrate; pellucid glands scarcely visible.

The ngaio scrub is exposed to constant winds bearing salt spray. The upper surface of the foliage, therefore, slopes gradually upwards from the outer edge of the scrub, where it reaches the ground. The soil is of the driest character, and in several places completely undermined by burrowing shearwaters. On Meyer Island one colony of birds succeeds another, so that the soil never has a rest.

On the east coast of Sunday Island a belt of ngaio scrub extends from the rocky shore back for several metres to the base of the cliffs, or, in Coral Bay, to the forest proper, which begins at –15 m. from the shingle beach. The effect of the easterly winds on this belt is most pronounced in Coral Bay. The Myoporum forms a close, compact mass, beginning with plants appearing among the rocks and only a few centimetres tall, and gradually getting higher towards the forest, where the adjoining Metrosideros trees have the wind-shorn habit of the Myoporum. At 10 m. from the shingle the average height would be about 1.5 m. All twigs appearing above the general level of the foliage are killed by the wind. Intermixed among the Myoporum are Macropiper excelsum major, Pteris comans, Carex Forsteri insularis, Sicyos australis, and Canavalia obtusifolia. The scrub in Coral Bay extends to the limits of vegetation along the shore, so that no line can be drawn between it and rock vegetation.

The western Terrace is covered with ngaio scrub, which increases in height from the top of the sea-cliffs towards the base of the higher cliffs

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at the back. The soil is completely overturned once a year by blackburrowers (Puffinus chlororhynchus), and this has the effect of almost killing the vegetation. The plants die down so much that there is hardly a green leaf left, and they have the appearance of being dead. When the birds depart, a fresh rank growth of foliage results from the large amount of guano left in the soil. In August a dense growth of young shoots covers the stems of Myoporum lœtum and Melicope ternata; the tops of the trees, however, are quite dead, and never recover. The undergrowth is a rank mass of Macropiper excelsum major about 1 m. high, and which, judging by the number of dead stems present, appears to have been killed right down to the roots. With it occur a few other plants—Mariscus ustulatus, Pteris comans, Solanum nigrum, Carex Forsteri insularis, Sicyos australis, Hypolepis tenuifolia, Ageratum conyzoides.

Growing in highly manured ground vacated by the shearwater above mentioned, Sicyos australis frequently produces abnormal male flowers, in which the petals turn green, and assume more or less the shape and character of young foliage-leaves.

The vegetation on Meyer Island takes the form of open ngaio (Myoporum) scrub up to about 8 m. high, and including some other trees not characteristic of this formation—Metrosideros villosa, Corynocarpus lœvigata, Pisonia Brunoniana, Rapanea kermadecensis.

Pisonia Brunoniana branches in an extremely irregular, not to say fantastic, manner. The trunk is stout, gnarled, and divided half a metre or so above the ground. The stems spread out in all directions, and, branching but few times, bear a rosette of large leaves at the extremity of each twig. Often large branches are dead. The Pisonia appears to have a hard struggle to live on this exposed arid islet. On every possible spot a whitecap noddy (Micranous leucocapillus) has placed its nest, built of Pisonia and other leaves. Whether or not the bird plucks leaves from the trees for its nest I cannot say.

There are a few small plants of Corynocarpus lœvigata growing in the most sheltered places on Meyer Island. They have erect stems, small, dark, yellowish-green upper leaves and larger lower ones, and, never rising higher than the surrounding ngaio scrub, their uppermost twigs are dead.

Asplenium Shuttleworthianum on Meyer Island is a low densely tufted fern. Rhizome stout, brownish-black, forming a mass –20 cm. in diameter. Fronds crowded, much divided, the pinnæ usually overlapping, with short segments, yellowish-green, the tips usually dead.

The soil on Meyer Island is the loose, shifting, yellowish, weathered surface of the tuffs of which the island is composed. It is continually being overturned by burrowing species of shearwater. During the summer months the burrows are occupied by Puffinus chlororhynchus, in company with a small petrel (Œstrelata nigripennis), while for the remainder of the year their place is taken by P. assimilis. It is only in crevices of rocks and other places where the birds are unable to burrow that any small plants occur. Here are found Sicyos australis, Canavalia obtusifolia, Parietaria debilis, Mariscus ustulatus, Solanum nigrum (pubescent form), Asplenium Shuttleworthianum, and Siegesbeckia orientalis.

The scrub, owing to the steep rocky nature of the surface, is rather open. The Myoporum itself appears to be as much dead as alive. Looking at it from above, one sees a forest of straggly dead brushwood, among which living branches are struggling for existence. The constant winds laden

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with salt spray are too severe, the result being that the upper exposed twigs of all the trees are dead.

The top of Dayrell Islet supports a very scanty vegetation. The soil is everywhere undermined by burrowing shearwaters, and is in every way similar to the steep slopes of Meyer Island. There are a few small trees of Metrosideros villosa of a straggly habit, while Myoporum lœtum and Coprosma petiolata form low dense bushes about 1 m. high.

(d.) Sand Dunes.—The only true sand dunes on Sunday Island form a single line fringing Low Flat Beach on the north coast. They are low, and consist of the fine sand of which the beach is composed, heaped up by wind against the land. They are covered with Ipomœa pes caprœ, which sends its runners two or three metres on to the beach itself, and its long white roots still further under the beach. Among the Ipomœa are found chiefly Imperata Cheesemani, Scirpus nodosus, Eleusine indica, and Apium prostratum.

(e.) Gravel Flat.—A flat extends along the beach in Denham Bay for about 2 km., and has an average width of 75 m. Its outer edge coincides with the limit of storm seas and shifting gravel; along its inner edge is forest. The vegetation of this flat forms an important plant formation, as in Denham Bay seeds of plants brought by ocean-currents and washed ashore are most likely to find a suitable place for germinating.

The principal plants of the gravel flat are Ipomœa pes caprœ, Mariscus ustulatus, Scirpus nodosus, Scœvola gracilis, Myoporum lœtum, Ageratum conyzoides, Stellaria media, Euphorbia Peplus, Cynodon Dactylon, Calystegia Soldanella, Tetragonia expansa, Deyeuxia Forsteri, Imperata Cheesemani, and Erechthites prenanthoides.

Ipomœa pes caprœ has long, branched, trailing stems, which lie along the ground, rooting here and there at the nodes. Leaves large, 2-lobed, dark yellowish-green, firm in texture, forming a mass of vegetation covering the ground to a height of 30 cm. Flowers large and conspicuous, pale lilac, produced in abundance.

Scœvola gracilis is a procumbent undershrub with long, spreading, hairy branches, and rather dense hairy foliage, covering the ground to a height of about half a metre. Leaves 114 x 39 mm., 110 x 42 mm., 97 x 35 mm., 80 x 25 mm., yellowish-green, firm in texture, covered with short stiff hairs. Flowers small, axillary, white with a yellow centre, produced abundantly throughout the year. Fruit fleshy, white.

Myoporum lœtum occurs on the gravel flat as low shrubs, 1–3 m. tall, with dense light-green foliage, through which project numerous dead twigs. Detached plants only are found, with the foliage on the seaward side reaching the ground.

The gravel flat is said to be covered by hurricane seas only, though other heavy seas sometimes break over parts of it, killing some of the vegetation. In July, 1908, the sea flooded part of the flat, and killed Ipomœa pes caprœ, and some of the leaves and twigs of Myoporum lœtum.

The soil is gravel, similar to that of which the beach is composed. During westerly weather it is continually drenched with salt spray.

From October till April, wideawake terns (Sterna fuliginosa) occupy the front portion of the gravel flat, and keep the vegetation well trampled down. When they depart, however, the Ipomœa pes caprœ grows up tall and rank, covering the ground with dense dark-green foliage to a height of –50 cm., and elsewhere a host of weeds, chiefly Stellaria media and Euphorbia Peplus, soon springs up.

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Three plants occupy practically the whole of the flat—viz., Mariscus ustulatus, Scirpus nodosus, and Ipomœa pes caprœ. Mariscus ustulatus occurs all over the flat, but more sparingly near the forest, where it is replaced by Scirpus nodosus and Ageratum conyzoides. Ipomœa pes caprœ grows almost everywhere, mixing with both Mariscus and Scirpus. Its long trailing stems are only driven back by the waves on one side and by the shade of the forest on the other. A few shrubs of Myoporum lœtum occur here and there, while there is an undergrowth among the Mariscus and Ipomœa, chiefly composed of Stellaria media, Euphorbia Peplus, and Cynodon Dactylon. Along the sea-edge, where the gravel takes the nature of a dune, Calystegia Soldanella and Tetragonia expansa occur.

There is evidence that another plant—Scœvola gracilis—now almost entirely killed by introduced sheep and cattle, formerly took an important part in the formation. In an enclosure at the south end of Denham Bay, where these animals are not allowed, the vegetation is dense, about half a metre high, and composed principally of Scœvola gracilis and Scirpus nodosus, with Ipomœa pes caprœ growing among them. Here also are found Imperata Cheesemani and Danthonia pilosa.

2. Inland Edaphic Formations.

The plant formations occurring in all places on Sunday Island where the nature of the soil inhibits the growth of forest (except the areas occupied by the coastal, young, and introduced formations) are included under this heading, and naturally fall into three groups, which will be described in the order of their probable appearance. Forest, being the only climatic formation, is kept under a separate heading, though true forest possibly existed on Sunday Island before there were any swamps or lakes.

(a.) Rocks and Cliffs.—On Sunday Island it may be said with regard to cliff vegetation that some of the plants now most characteristic of it are those which goats search out and suppress in the forest. This is certainly the case with Asplenium Shuttleworthianum and Veronica breviracemosa. Certain plants, however, such as Lagenophora petiolata and Lobelia anceps, are found in nearly all rocky places in the forest. Other species usually occurring in rocky situations are Hydrocotyle moschata, Coprosma petiolata, Carex Forsteri insularis, Scœvola gracilis, Cyclophorus serpens, Peperomia Endlicheri, Poa polyphylla, Mesembryanthemum australe, and Psilotum triquetrum.

The rock-vegetation is well developed on the cliffs at the back of the Terraces. These cliffs are of an exceptionally dry character, face north, and are inaccessible to goats. Where there is a crevice or ledge affording the slightest hold for soil, plants will be found. The chief members are Cyclophorus serpens, Lobelia anceps, Asplenium Shuttleworthianum, Poa polyphylla, Peperomia Endlicheri, and Mesembryanthemum australe. A plant of Coprosma petiolata was also seen.

On the cliffs above Denham Bay, now, owing to the presence of inhabitants in the bay, practically free from goats, are found Veronica breviracemosa, Coprosma petiolata, Lobelia anceps, Lagenophora Forsteri, and Carex Forsteri insularis, besides Hydrocotyle moschata in damp places. On an open rocky slope Scœvola gracilis covers the ground; mixed with it is a little Danthonia pilosa.

A cliff in the crater at the base of Moumoukai contains the following plants: Poa polyphylla, Cyclophorus serpens, Scœvola gracilis, Erechtites

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prenanthoides, Nephrolepis cordifolia, Adiantum hispidulum, Pellœa falcata, Ageratum conyzoides, and dwarf plants of Myoporum lœtum and Coriaria sarmentosa. This part was included in the area destroyed by a volcanic eruption in 1872.

At the foot of the cliffs in Denham Bay steam escapes in several places, killing the vegetation where it issues from the ground. Near by, on the warm ground, is a dense growth of plants ½-1 m. high, consisting chiefly of Nephrolepis exaltata, Polypodium diversifolium, Paspalum scrobiculatum, Lycopodium cernuum, and Psilotum triquetrum. The Polypodium and Lycopodium have tall erect fronds, the former measuring up to 105 cm., the latter to 83 cm., in height.

On Macauley Island deep ravines, cut through volcanic tuffs by the action of rain-water, support on their precipitous sides a little vegetation. Goats are unable to reach certain parts, and hence possibly a remnant of the original vegetation is found here. These gullies afford shelter from wind, but the porous nature of the ground allows water to percolate freely; hence the soil is usually particularly dry. The list of plants noticed in these ravines is as follows: Boehmeria dealbata, Carex Forsteri insularis, Asplenium lucidum, A. obtusatum, Hypolepis tenuifolia, Poa polyphylla, Lobelia anceps, Gnaphalium luteo-album, Scirpus nodosus, Mariscus ustulatus, and Mesembryanthemum australe.

(b.)Swamp.—Swamp occurs in Denham Bay and round the Blue Lake in the crater. Typha angustifolia grows along the edges of Tui Lake and the Green Lake, but there is no swamp formation.

The swamp in Denham Bay is situated opposite the middle of the bay, between the gravel flat and the high perpendicular cliffs some 300 m. further back. It is somewhat oblong in shape, about 600 m. long and 200 m. broad. The ground round the swamp is composed of pumiceous tuffs and gravel, derived from the cliffs, which no doubt slipped down into the bay when the sea washed their bases. The sea has since retired, being now some 400 m. from the cliffs at this part. Rain-water percolates these tuffs very quickly, but under the swamp is a layer of blue and yellow sandy clay which holds water for a considerable time, thus making possible the existence of a swamp. The surface is everywhere spongy and gives under the feet. In places, more especially after rain, water lies to a depth of 20 cm.

The principal swamp-plant is Typha angustifolia. Its height varies. Over the greater part of the swamp it lies between 1 m. and 1.5 m., and here the ground, though springy, will support the weight of a man. In places, however, it is tall, up to 2.6 m., and here one's legs sink in up to the knees or deeper. After the Typha, Juncus effusus is the most important plant. It grows in tufts, 1.5 m. high, and covers large patches in the drier parts of the swamp. Blechnum capense (75 cm. tall), Histiopteris incisa, and Paspalum scrobiculatum occur in small patches in several places. The Histiopteris forms rather dense patches ± 1 m. high, with much decayed vegetable matter underneath. Other swamp-plants noticed were Juncus pauciflorus near the edge, and Heleocharis acuta in water.

The character of the vegetation in the Denham Bay swamp appears to be altering, forest-plants taking the place of swamp-plants. In fact, a swamp formation is here in process of being changed into forest. Thirty years ago there was an open sheet of water with Typha angustifolia growing along the edge, from where gradually it spread until now there is no open water. Parts, however, are much wetter than the rest, and here the Typha

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is tallest. In the greater part of the swamp the following appear to be sings of drying up: Typha angustifolia is of small size; Juncus effusus is abundant; various other plants, such as Mariscus ustulatus, Ageratum conyzoides, and Polypodium diversifolium, are appearing; and, finally, plants of Metrosideros villosa up to 2 m. in height occur in various places, chiefly on the higher ground, where water does not actually lie on the surface. The cause of this change is probably the filling-in of the swamp by material washed into it by rains.

The swamp surrounding the Blue Lake is similar to that in Denham Bay, but contains fewer species of plants. Besides Typha angustifolia, Mariscus ustulatus and Paspalum scrobiculatum are the chief plants. This swamp is of recent origin, as the water in the Blue Lake was probably boiling during the eruption of 1872, there being a number of standing dead trees near its shores.

(c.) Lakes.—From the edge of the Green Lake the bottom slopes steeply into deep water. In places, however, there is a shelf just submerged, and here Typha angustifolia finds a foothold; but in all cases there is a space of about a metre between it and the water's edge, this being the distance goats are able to reach when standing in shallow water.

Tui Lake is a small sheet of fresh water surrounded by forest, and lies on the edge of the area affected by the eruption of 1872. A little Typha angustifolia occurs, and Callitriche Muelleri grows either entirely submerged or on the bank close to the water's edge.

3. Forest Formations.

(a.) General Remarks.—Practically the whole of Sunday Island is covered with forest, this being the true climatic plant formation. The proportion of ground occupied by other formations would be insignificant when compared to that under forest, which reaches from the water's edge to the tops of the highest hills, were it not for certain disturbing influences which may be termed accidental, and which have led to the existence of the plant formations described below as “young” and “introduced.” But climate, being a permanent unchanging factor, must in the long-run overcome any temporary disturbing influences, and consequently forest will gradually replace the new formations. This process is certainly going on with regard to the young formations, which might appropriately be called young forests; but the occupation of man, which is responsible for the existence of the introduced formations, may become a permanent factor ever preventing the forest regaining its lost ground. I have already mentioned the change which is apparently taking place in the swamp in Denham Bay; but this is a slow, natural process consequent on the filling-in of the swamp by material washed into it by rains, and, possibly, the gradual upheaval of the Kermadec Islands plateau.

Though small, Sunday Island is hilly in the character of its surface, and a considerable area is over 300 m. above sea-level; hence the amount of atmospheric precipitation is not the same in all parts, and consequently the character of the forest varies. The soil is everywhere extremely permeable, so that it may be disregarded as a factor determining the distribution of the main types of forest. The more elevated parts of the island undoubtedly receive a much greater amount of moisture than the lower parts. In northerly weather everywhere above an altitude of about 300 m. is enveloped in clouds, while the lower ground receives moisture only while it is

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actually raining, and between showers may even be suffering from the desiccating effect of the wind.

The forest, then, may be divided into two main types, determined by the amount of moisture received. To these I apply the terms “dry” and “wet.” I might also refer to them as “upper” and “lower”; but, though the wet forest is confined to the upper parts of the island, its existence as a distinct formation is not due directly to its altitude, but to its abundant supply of moisture.

Generally speaking, the wet forest occurs on ground more than 250 m. above sea-level, though no sharp line of demarcation can be drawn between the wet and dry forests, the one passing gradually into the other at an altitude varying between 200 m. and 300 m. It differs from dry forest in its much more luxuriant growth, and in the abundance of cryptogamic epiphytes.

(b.) Leading Physiognomic Plants and their Life-forms.—(1) Trees and shrubs: Metrosideros villosa occurs in two principal forms. Its ordinary state is a lofty forest-tree, 20 m. tall, with an erect, more or less crooked or twisted trunk ½—1 m. in diameter at the base, and branching, chiefly in its upper part, in a most irregular manner. Aerial rootlets are usually given out from the lower part of the trunk. These grow downwards, increasing in size and branching till they reach the ground, where they take root, and, still growing larger, act like additional stems.

The larger trees on the ridges and in exposed places usually have immense prostrate trunks, sending up several branches each the size of a large tree. Aerial roots are given off from the under-side of the trunk until the base of the tree becomes a mass of entangled roots and stems of all sizes. In leaning trees they form supports for the trunk, which thus spreads in the direction in which it is leaning—usually downhill or in a northerly direction—that is, away from the point whence come the hurricanes.*

Corynocarpus lœvigata is a lofty forest-tree, 20 m. tall, with one to three erect stems, branching chiefly about 8–10 m. above the ground. The three trunks of one tree measured 115 cm., 135 cm., and 150 cm. in circumference respectively. Bark dark brown, rather rough, with small lenticels. Foliage dense.

Myoporum lœtum is a lofty forest-tree, 20 m. tall, with a trunk 2 m. in circumference at the base, branching near the top, and with lax foliage. Bark rough, grey. Leaves serrate, light green, pellucid glands scarcely visible. Usually in the forest Myoporum lœtum is a small tree of the second tier, with an erect stem and lax foliage.

Melicytus ramiflorus in dry forest is usually a small tree with an erect branching stem and lax foliage. In wet forest, however, it is a tree of large proportions, consisting of a great many stems spreading from the base, and with the moderately dense foliage borne principally at the top. Bark nearly smooth, and of a light-grey colour.

Rapanea kermadecensis is a small glabrous tree, 6–10 m. tall, with an erect stem bearing numerous horizontal branches. Bark rather smooth, with small lenticels, reddish-grey. Wood extremely hard. Foliage dense. Leaves elliptic-oblong, coriaceous, dark green, margins wavy, more or less rolled; laminæ 42 x 20 mm., 45 x 25 mm., 60 x 27 mm., 70 x 33 mm.

[Footnote] * Dr. Cockayne is of opinion (Report Bot. Surv. Stewart Island, 1909, p. 10) that Metrosideros lucida has under certain stimuli an hereditary tendency towards a prostrate habit.

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Flowers small, in fascicles on the twigs among and below the leaves. Fruit fleshy.

Ascarina lanceolata is a tall shrub or small slender tree, with bark of a dark reddish-brown cólour, and rather rough, with close lenticels. Foliage dense; leaves ovate-lanceolate or oblong-lanceolate, deeply serrate, firm in texture, aromatic: laminæ 55 x 18 mm., 62 x 24 mm., 65 x 20 mm., 65 x 22 mm. Flowers unisexual, in compound spikes. Fruit a small drupe, 3 mm. long.

Melicope ternata is a small erect tree, 10 m. tall. Bark rather rough, with numerous lenticels, reddish. Leaves trifoliate, in bunches at the end of the twigs; leaflets large, the central ones 15 cm. long, 7.5 cm. broad, shining, flaccid, or the older ones firm.

Coprosma acutifolia is a small, erect, often slender tree, 7–10 m. tall, and with a trunk sometimes 140 cm. in circumference near the base. Bark quite smooth, grey to greenish. Branches ending in numerous slender twigs bearing moderately dense foliage. Leaves ovate-lanceolate to ellipticovate, acuminate, variable in size and shape; laminæ 43 x 18 mm., 63 x 22 mm., 75 x 35 mm. Fruit small orange-red drupes, produced copiously.

Macropiper excelsum major is a small shrub, 2–3 m. tall, with usually several stems springing from the same base. Stems smooth, greenish, terete, with large nodes. Foliage lax. Leaves large, cordate, with 7–13 ribs radiating from the base, flaccid or moderately firm in texture; laminæ 12 x 11 cm. to 16 x 19 cm. (largest leaf measured 17 x 22 cm.). Flowers diœcious; male spikes –23 cm. long, female spikes 8–10 cm. long. Fruit fleshy.

(2.) Palms: Rhopalostylis Baueri has a stout, erect, terete, greenish trunk, marked by conspicuous regular rings representing leaf-scars. Base of stem enlarged, bearing densely crowded short roots. Height to flowers 7–10 m. Flowers borne at the base of the leaf-sheaths, several succeeding one another in a season. Leaves pinnate; length without sheath 3.5 m., longest pinnæ 1–1.2m., forming a crown at the top of the stem spreading at an angle of ± 130°.

(3.) Tree-ferns: Cyathea kermadecensis has a trunk –20 m. tall, the base large, 1–2 m. in diameter, formed of adventitious rootlets and rapidly narrowing into a slender upper part which is comparatively smooth, as the fallen fronds leave clean scars.

Cyathea Milnei has a stout erect trunk 4–8 m. tall, slightly thickened by adventitious rootlets at the base. Fronds after withering hang down the stem for a considerable time, hence there is always a cluster of dead fronds round the top. When they do fall they break off short, leaving the broken stipes attached to the trunk, which consequently is rough and untidy.

(4.) Small ferns: Pteris comans forms tufts about 2 m. tall, containing many dead stipes besides the living fronds.

Nephrolepis exaltata has a short erect rhizome from which fronds and roots spring crossing one another. Height 1–2 m. A frond measured—stipe, 100 cm.; frond, 113 cm.; total length, 213 cm.; longest pinna, 175 x 17 mm. Pinnæ easily broken, so that perfect specimens are rare.

Nephrolepis cordifolia is a low fern with a tufted rhizome bearing 6–10 live and many dead fronds, and numerous roots forming a tangled mat. Fronds linear, –60 cm. long, 5–6 cm. broad, with the pinnæ usually broken near their tips.

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Polystichum aristatum has a long creeping rhizome bearing at short intervals erect, hard, dark-green, deltoid fronds, 1 m. tall.

Dryopteris setigera is a tall fern, 1–2 m. high, with a short tufted rhizome and few, light-green, delicate, compound, deltoid fronds.

Diplazium japonicum is a low tufted fern, about ½ m. tall, with few light-green, delicate, pinnate fronds.

Blechnum capense varies very much in its size and habit. It may be a tall fern with erect fronds 2–2.5 m. high, or a low fern, ½m. tall, with broadly ovate or nearly orbicular spreading fronds.

(c.) Ecology.—(1.) Ecological factors: First in importance of factors determining both the existence and character of the forest is climate. An abundant supply of rain spread throughout the year produces a forest formation whose physiognomy alters in accordance with the amount of moisture received. A full account of the climate has already been given. The annual rainfall, amounting to over 1,700 mm. for nine months, and high average degree of relative humidity, with a temperature never falling below 8°C., and averaging more than 18°C., is ample to produce hygrophytic vegetation (16; p. 168), while the desiccating effect of the constant winds is to a certain extent counterbalanced by the moisture-laden atmosphere. The winds are most felt near the sea-shore and at the top of sea-cliffs, where the vegetation is shorn down to a certain height, above which nothing but dead twigs project.

The general effect of the warm and humid climate on the vegetation is to promote a luxuriant growth. This is exemplified in the case of New Zealand plants extending to the Kermadecs. Macropiper excelsum and Melicope ternata are each represented by varieties characterized by larger leaves. Corynocarpus lœvigata and Myoporum lœtum, small trees in New Zealand, are on Sunday Island lofty forest-trees 20 m. tall. The habit of two plants—Calystegia Soldanella and Ipomœa palmata—of flowering but not fruiting (according to my observation) is perhaps occasioned by the climate. Some mosses rarely bear fruiting capsules.

A number of plants flower immediately after fruiting. In the case of Rapanea kermadecensis both flowers and ripe fruit are sometimes seen on the same twig. Besides this species, Coprosma petiolata, C. acutifolia, Macropiper excelsum major, Ascarina lanceolata, and Melicope ternata flower during the winter months. The slight fall in temperature, rather than interfering with, seems to favour the development of the reproductive organs (see 16; p. 48).

In the list of indigenous plants I have recorded the measurements of large specimens of several plants.

The most noticeable effect of winds is to limit the general level of the vegetation in exposed places. Myoporum lœtum, which is the principal plant in the coastal scrub, adapts itself precisely so as to offer least resistance to the prevailing winds. Its slanting flat top is maintained by the constant winds, which, laden with salt spray, kill every twig above a certain level, determined by the density of the foliage. On the tops of cliffs, where the wind strikes with full force, the foliage is shorn down to a certain height, above which only dead twigs project.

Soil is a factor second in importance only to climate. There is little variety of soils on Sunday Island, any difference between one and another consisting in the proportions of vegetable matter contained in each. The soil everywhere consists of the more or less altered—by weathering and

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admixture of vegetable humus—surface of tuffs composed for the most part of pumice. The tuffs themselves are of an extremely porous character, and any noticeable water-holding capacity the soil may possess is due to the addition of humus. The nature of the soil, then, is such as to hinder the growth of forest, which depends as a formation on an abundant supply of atmospheric moisture.

On the lower more level ground a layer of black loam –20 cm. deep rests on pumice tuffs. Water percolates freely; hence the ground is usually more or less parched. On the hilltops, however, the more abundant supply of moisture promotes a luxuriant growth, and the consequent decay of vegetation adding humus to the soil increases its water-holding capacity. No water lies on the surface, though the soil is usually moist, and a layer of dead leaves prevents it rapidly becoming dry. On the hillsides the weathered surface of the tuffs forms the soil.

The density of the forest-roof, by regulating the supply of rain and light, has a direct bearing on the distribution of the undergrowth. The vegetation on the forest-floor varies from a dense growth of ferns 2 m. high to a few scattered ferns and seedlings, whilst in places it is entirely absent, there being only dead leaves and branches lying about. As a general rule, where the foliage is most dense there is little undergrowth, but where a break occurs ferns and other plants are abundant. On the hilltops, however, where clouds hang about in northerly weather, more moisture will be supplied to the undergrowth, which is therefore usually most luxuriant, notwithstanding the fact that the forest-roof may be not less dense than it is on the lower ground. In Denham Bay there is everywhere a dense undergrowth. Climatological Table II shows that on Sunday Island three-fourths of the rainfall occurs during northerly weather. Rain-clouds impinging against Big and Expedition Hills drop their moisture on the summits of these hills and on the flat in Denham Bay directly below.

(2.) Trees: The trees are all evergreens. One only exhibits partial defoliation. In the winter months Homolanthus polyandrus has appreciably fewer leaves on it than it has in the spring and summer. The older leaves fall away in the autumn, leaving only those on the young shoots, and usually less than 10 cm. across.

Two sizes of trees are distinguishable in the dry forest—those which form the upper or third tier of vegetation, which varies from 15 m. to 20 m. in height, and those growing in the shade of these, and forming a second tier of vegetation. Four trees are included in the first category—Metrosideros villosa, Corynocarpus lœvigata, Myoporum lœtum, Melicytus ramiflorus. In the wet forest a third tier of vegetation cannot be distinguished, the general height of the formation being about 10 m.

Over the greater portion of Sunday Island a moist climate and dry soil require that the trees should be able to endure frequent short droughts, and at the same time hold their own against hygrophytes. The soil decides the battle in favour of the plants least affected by drought. Rolled leaves, which I suspect are an adaptation to situations exhibiting alternately wet and dry conditions, are a conspicuous feature in the Sunday Island vegetation, not on account of the number of species, but because of the preponderance of individual plants, possessing them. In Rapanea kermadecensis, an important plant in dry forest, and Coprosma petiolata, a characteristic shrub of the coastal formations, the whole leaf rolls inwards so that opposite sides of the upper surface may be touching. Both these plants are endemic; hence the adjustment of their organs to the environment is complete.

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In Metrosideros villosa the margins of the leaves are more or less recurved. The leaves of the three above plants agree very closely in size, shape, and texture. They are small, entire, oblong, coriaceous, with their margins recurved or more or less rolled.

In wet forest, where more hygrophytic conditions prevail, Metrosideros and Rapanea cease to be the dominant plants, and the leaves are of a less pronounced xerophilous character.

Leaf-buds are protected, probably against desiccation, in various ways. In Homolanthus polyandrus two imbricate bracts enclose each of the delicate young leaves until they expand. In Macropiper excelsum the sheathing base of the petiole of the terminal leaf contains the leaf-bud. In Nothopanax arboreum the bud is covered with mucilage. Metrosideros villosa and Pittosporum crassifolium have the buds covered with dense white tomentum.

Partial cauliflory is exhibited in Rapanea kermadecensis and Melicytus ramiflorus.

Diœcious flowers occur in Melicytus ramiflorus, Macropiper excelsum major, Coprosma acutifolia, C. petiolata, and Nothopanax arboreum.

Aerial roots are produced abundantly in Metrosideros villosa. The wetter the situation the greater the profusion of roots. In wet forest the prostrate trunk of a tree may be a metre above ground, supported by hundreds of large and small root props, and sending up large branches like distinct trees.

Ornithophily is exhibited especially in Metrosideros villosa, which has flowers with a brushlike polyandrous andrœcium, and a supply of nectar at the base. The tui (Prosthemadera novœ zealandiœ) is certainly instrumental in effecting cross-pollination for this species. These birds are abundant on Sunday Island, and may frequently be seen, with a yellow patch of pollen at the bases of their bills, visiting the flowers of the Metrosideros.

Entomophily occurs with Melicytus ramiflorus. Lacewings were observed visiting the flowers of both male and female plants, apparently searching for nectar, which I suspect is secreted by the glandular organs at the base of the petals. The lacewing thus unintentionally carries away from the male flowers pollen adhering to the under-side of the thorax. Should the insects afterwards visit female flowers, the pollen would cling to the viscid surface of the stigma, and fertilisation be effected.

The reproductive organs of Macropiper excelsum major, Homolanthus polyandrus, Coprosma acutifolia, and C. petiolata are adapted for wind pollination.

(3.) Epiphytes: With one or two unimportant exceptions the epiphytes on Sunday Island are cryptogams. They are a conspicuous feature of wet forest, where almost every available space on trees, palms, and tree-ferns is covered with mosses and ferns. Elsewhere they are much less abundant. The large leaning stems and horizontal branches of Metrosideros villosa support a thick covering of mosses, among which grow a variety of ferns. In the wet forest the rough stems of tree-ferns (Cyathea) are often clothed with filmy ferns and mosses, whilst even the smooth stem of Rhopalostylis Baueri is sometimes hidden by a mantle of mosses and ferns.

The principal epiphytes are Cyclophorus serpens, Polypodium diversifolium, Asplenium flaccidum, A. caudatum, Nephrolepis cordifolia, Trichomanes venosum, Hymenophyllum demissum, H. flabellatum, Tmesipteris tannensis, Lycopodium Billardieri, Acianthus Sinclairi, and Peperomia Endlicheri.

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Mention has already been made of two plants (Metrosideros villosa and Nothopanax arboreum) which frequently pass through the first stages of their development on tree-fern stems, but subsequently become connected with the ground by their roots.

(4.) Ferns: Ferns may conveniently be divided into three ecological groups—tree-ferns, filmy ferns, and other kinds.

The first group is represented on Sunday Island by two endemic species, which, however, differ in many important points.

Cyathea kermadecensis is characteristic of the wet forest, and in places is the dominant plant. What may be termed a Cyathea forest exists in places, where magnificent tree-ferns, 20m. tall, form a distinct plant association, forest-trees taking but a subordinate part. The fronds are rather flaccid in texture, and in dry weather curl up their pinna-segments. As they wither they fall, leaving the top of the trunk bare, and this habit gives the fern its graceful appearance. Adventitious roots are developed at the base of the trunk until it assumes large dimensions. Growing on hillsides the plants are usually leaning, and the adventitious roots are given out most abundantly on the under-side, where most of the rain-water running down the stem naturally flows before reaching the ground. Here the base of the trunk forms an acute angle, and a cross-section would be somewhat kite-shaped, about 2m. one way and 1m. the other.

Cyathea Milnei, the more common tree-fern in dry forest, has hard coriaceous fronds, which clothe the top of the trunk as they wither. Adventitious roots form a conical base sometimes nearly 1m. in diameter.

The filmy ferns, of which there are four species on Sunday Island, have delicate fronds formed of but a single layer of cells. In dry weather the fronds curl up and the tips wither to a certain extent, and, if the drought be lasting, do not recover; hence it is a common thing to see these ferns with the edges of their fronds dead.

Hymenophyllum demissum is abundant everywhere in wet forest, on branches of trees, tree-fern stems, and on the ground. Large fronds measure, including the stipes, 36cm. in length. In dry forest a few small sickly-looking plants were noticed on a log in Denham Bay. H. flabellatum was found in one place only—the matted roots and close fronds covering the under-side of a leaning trunk of Metrosideros villosa on the summit of Moumoukai. The fronds were small, 6–7cm. long, with close overlapping segments, dead at the tips, and filiform stipes, 1–14cm. in length.

Trichomanes humile, with fronds 7–11cm. long, was extremely rare, being found only on wet banks and fallen trunks of tree-ferns in deep shady ravines. T. venosum is an epiphyte of the wet forest found only on the under-side of leaning trunks of Cyathea kermadecensis. In its ordinary state the frond is broadly ovate, 7–8cm. long, 3–5cm. broad, with a short filiform stipe 2–3cm. long; but when growing far in under a trunk it is linear, –14cm. long, 1.5-2cm. broad, with a stipe 2.5-5cm. long. One frond, including stipe, measured 17.5cm. in length, 2cm. in breadth.

Of other kinds of ferns entering largely into the forest formation Pteris comans, Polystichum aristatum, and Nephrolepis exaltata are the chief in dry forest. All have coriaceous fronds. In wet forest Dryopteris glabella and Blechnum norfolkianum are abundant. The texture of their fronds is firm but scarcely coriaceous, and in their young states very delicate. B. norfolkianum often has a small erect rhizome 10cm. high, bearing the fronds in a tuft near the top.

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(d.) Physiognomy.—The wet-forest formation covers the top of the crater-ridge from Moumoukai to Expedition Hill, and the ridges running south-west from Mount Junction to Bollons Peak, and north-west from Expedition Hill, over Big Hill, towards Hutchison Bluff. The height of this area above sea-level is mostly over 300m., but wet forest extends below this limit on the southern sides of the ridges and in deep gullies. The remainder of the forest on Sunday Island is of the dry type. There is no sudden change noticed in ascending the hills from sea-level to their summits, as dry forest passes gradually over into wet forest. Between typical wet forest and ordinary dry forest, however, there is a marked difference. In the transition forest a mixture of plants occurs, and Ascarina lanceolata is found in company with Rapanea kermadecensis shaded by tall Metrosideros villosa.

(1.) Dry forest: Viewed from above, the dry forest presents a sombre appearance, the dark-green foliage of Metrosideros villosa alone being visible. By about June the monotony is relieved by the appearance of young shoots covered with white tomentum, and later, in October, some trees begin to flower, but not till late in November is the flowering general. Then the forest must be a blaze of red, for the scarlet flowers are produced in great profusion, but by the end of the year they are mostly over, and dull-green foliage again dominates the landscape.

The general height of the dry forest is about 20m., and three tiers of vegetation may be distinguished. In places the forest-floor is strewn only with dead leaves and twigs, and there is no undergrowth. Usually, however, an undergrowth is present, varying in its composition in different parts. A dense growth of Pteris comans 2m. high forms the lowest tier of vegetation in many portions of the island. Intermixed with this fern are Macropiper excelsum major, Polystichum aristatum, Doodia media Milnei, Oplismenus undulatifolius, Adiantum hispidulum, Blechnum capense, Dryopteris setigera, and other plants.

On Low Flat Cenchrus calyculatus is abundant, and at the base of the cliffs in Denham Bay Hypolepis tenuifolia, with fronds 3–4m. tall, is plentiful.

In Denham Bay Nephrolepis exaltata forms an almost impenetrable mass of vegetation 1–2m. high, with few other plants intermixed. Polystichum aristatum also forms the undergrowth in various parts of the island, and in Denham Bay Nephrolepis cordifolia claims areas to the exclusion of all other plants, its matted roots spreading over the ground, over fallen logs, and ascending the stems of tree-ferns.

Seedlings of trees, notably Corynocarpus lœvigata, and the palm Rhopalostylis Baueri, often form thick patches on the forest-flocr.

In Coral Bay the undergrowth is a more or less dense growth of Macropiper excelsum major, difficult to get through. Mixed with it is a fair proportion of Pteris comans. The Macropiper plants have each several stems, sometimes 5m. long and 23cm. in circumference at the base, and arched in a more or less horizontal direction.

Thus several distinct plant-communities contribute to the undergrowth in the dry forest of Sunday Island.

The second tier of vegetation is composed of small trees, plams, and tree-ferns growing in the shade of Metrosideros villosa. The trees are usually erect, 6–10m. tall, branch little, and have lax foliage. They are not close together, and are altogether not so numerous as the stems of the Metro-

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sideros among which they grow. The principal plants of this tier are Melicytus ramiflorus, Rapanea kermadecensis, Coprosma acutifolia, Melicope ternata, Corynocarpus lœvigata, Myoporum lœtum, Coriaria sarmentosa, Boehmeria dealbata, Rhopalostylis Baueri, and Cyathea Milnei.

Near the coast, on Low Flat and other places, Pittosporum crassifolium occurs, while in Coral Bay and elsewhere are clumps of Pisonia Brunoniana, each tree stripped of its bark as far as goats can reach.

In the more sheltered places Rhopalostylis Baueri forms picturesque groves. There is seldom much undergrowth where these palms are plentiful.

The third tier of vegetation in the dry forest is composed almost exclusively of Metrosideros villosa 20m. tall. Two other trees, Corynocarpus lœvigata and Myoporum lœtum, occasionally equal the Metrosideros in height; while one, Melicytus ramiflorus, although not more than 15m. tall, sometimes claims a share in the upper tier of foliage. There are large Corynocarpus trees in several places, but the giant Myopora were only seen in the crater and on the Terraces. A large Melicytus on the Terraces measured 15m. in height, and had four principal stems, 80cm., 110cm., 110cm., and 125cm. in circumference respectively.

The forest-roof is usually fairly dense, and this factor determines the slender habit of the trees forming the second tier and regulates the distribution of the undergrowth.

Epiphytes are not a conspicuous feature in dry forest. The trunks of Cyatheœ occasionally support Tmesipteris tennensis, Asplenium caudatum, and Nephrolepis cordifolia. Branches of trees, especially the larger horizontal ones, and leaning stems, too, afford situations for a little moss, Cyclophorus serpens, Polypodium diversifolium, and Asplenium flaccidum (small erect form).

(2.) Wet forest: Unlike the dry forest, the wet forest is composed of a mixture of trees no one of which is predominant. Its appearance from above is varied by its different shades of green, while the graceful heads of palms and tree-ferns are thickly scattered about among the foliage. The average height on the summits of the hills is about 10m., but in valleys and on sheltered slopes the tree-ferns (Cyathea kermadecensis) are –20m. tall, and the forest-trees rather less.

On Moumoukai, the highest and wettest portion of the island, the forestfloor is everywhere covered with (1) mosses; (2) low ferns—Dryopteris glabella, Blechnum norfolkianum, Polypodium diversifolium, Hymenophyllum demissum; (3) dead leaves—notably Cyathea fronds and palm-leaves—and sticks; (4) roots of trees, fallen tree-fern stems, logs, &c., covered with mosses and the above four ferns.

Fallen trunks of tree-ferns are plentiful on the floor of the wet forest. These are invariably covered with mosses, Hymenophyllum demissum, Polypodium diversifolium, and on the under-side Trichomanes venosum, or perhaps T. humile.

On Big Hill the undergrowth is most dense, and there is a smell of rotting vegetation. Pteris comans is the principal plant, and its general height is 2m. Under the Pteris grow Dryopteris glabella and Blechnum norfolkianum.

The trees of the upper forest grow close together, average 10m. or more in height, and have much-branched heads of dense foliage.

Metrosideros villosa is here not the dominant tree, but is usually of large proportions, with immense prostrate trunks supported by numerous root props. The direction in which the trunk is lying is almost invariably north

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to north-west, and is undoubtedly the result of hurricanes which visit the islands occasionally and blow with great violence from the south-east. Rhopalostylis Baueri and Cyathea kermadecensis are abundant, and characteristic of wet forest. The principal trees are Melicytus ranuflorus, Ascarina lanceolata, Nothopanax arboreum, Coprosma acutifolia, and Rapanea kermadecensis. In a deep gully on Bollons Peak a single tree each of Homolanthus polyandrus and Boehmeria dealbata were noticed.

In a limited sense the plants of the wet forest group themselves into associations in which a single species is dominant. On Big Hill immense Melicytus ramiflorus trees, each with numerous stems, are most plentiful. On Expedition Hill and other places Ascarina lanceolata forms an association of tall slender trees, 8m. in height, bearing foliage and flowers at the top only.

But the most important and distinct of the subformations is that of Cyathea kermadecensis. On Bollons Peak a large area is occupied by this tree-fern, associated with a few forest-trees—Melicytus ramiflorus, Nothopanax arboreum, Ascarina lanceolata, and Metrosideros villosa. The treeferns are growing close together, and average about 20m. in height. The bases, composed of adventitious roots, are 1–2m. in diameter, and often three or four unite, forming a mass 3m. or 4m. through. Lying about the ground are numerous fallen trunks of tree-ferns and trees, all covered, like the standing tree-ferns, with mosses and ferns. The tree-fern trunks are thickly clothed with Hymenophyllum demissum, Trichomanes venosum, Asplenium flaccidum, A. caudatum, Polypodium diversifolium, and mosses. Pteris comans and Dryopteris glabella form what little undergrowth there is.

The luxuriant growth of epiphytic vegetation is the main feature which stamps the physiognomy of the wet forest. A third of the species of plants noted in wet forest are epiphytes, and only two of this number (11) also occur there on the ground. The trunks and branches of forest-trees and the stems of tree-ferns and palms are clothed with mosses and ferns. Even where the forest-floor is bare of vegetation, epiphytes are not any the less abundant.

Leaning trunks and horizontal branches of trees collect a lot of soil, on which several kinds of mosses and lichens, as well as a variety of ferns and two spermophytes, flourish. The following were observed in such situations: Polypodium diversifolium, Cyclophorus serpens, Asplenium flaccidum (two forms), Lycopodium Billardieri, Acianthus Sinclairi, Peperomia Endlicheri, Hymenophyllum demissum.

The trunks of tree-ferns are erect but rough. As a substratum for plants they become very dry in fine weather, while no soil was observed to collect on them. In the wet forest they are nevertheless invariably clothed with various species of mosses, Hymenophyllum demissum, Cyclophorus serpens, Asplenium caudatum, A. flaccidum (two forms), and Tmesipteris tannensis.

On the under-side of leaning fern-trunks where rain-water does not flow none of the above plants occur, but in such places Trichomanes venosum is found. It alone appears to be able to obtain sufficient moisture from the atmosphere to sustain life, while in places exposed to the weather it is apparently not able to hold its own against more hardy ferns.

Palm-stems, being smooth, do not afford stations readily occupied by epiphytes. In wet forest, however, they are usually clothed with mosses, Polypodium diversifolium, and Cyclophorus serpens.

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4. Young Formations.

In two places on Sunday Island the original dry forest has been destroyed, and young scrub or forest now occupies the ground. In Denham Bay a laergelandslip occurred about four years previous to my arrival. The whole face of the cliff up to 300 m. in height fell bodily forward on to the forest covered flat below, and vuried under about 10 m. of earth and rocks and area of 0.05 sq. km. About 1872—the date is uncertain—Sunday Island was in a state of eruption. From the Green Lake ashes, pumice, and boiling water ejected, and, falling upon the forest-covered crater-floor, destroyed the vegetation. Beyond the crater it extended over Mount Campbell on to Low Flat, and altogether covered an area of about 3 sq. km.

The formation belonging to this section, here called “young” formations, arse reversions (6; p. 26) to the first stages of the forest formations, with this difference: that some introduced species of plants enter into their composition, whilw introduced animals prevent the appearance of certain species of indigenous plants. In the next section the dominant speices of plant in each formation is itself introduced.

(a). Landslip.—The surfacse of thse Denham Bay landslip is extremely rough, being for the most part composed of large and small blocks of lava tufs idiscriminately piled one above another. Among these are patches of smaller stuff, gravel, &c., and it is in such places that plants obtain a footing. Everywhere except in one place, where there is a small pool in wet weather, water sinks in quickly. Logs are lying here and there, while round the edge is a belt of fallen dead trees.

The landslip is sparsely covered with vegetation—some of it with rounded shreubs, 4–6 m. tall, of Myoporum lætum and Coriaria sarmentosa, with a few small trees of Homolanthus polyandrus and Boehmeria dealbata; the remainder quite bare, of with a covering of Ageratum conyzoides, Scævola gracilis, Mariscus ustulatus, and small deedling Metrosideros villosa. Other plants noticed on the landslip were Halorrhagis erecta, Veronica breviracemosa, Coprosma petiolata, and Poa polyphylla.

(b.) Tutu (Coriaria) Scrub.—The soil in that portion of Sunday Island affected by the eruption of 1872 is the surface of the newly deposited pumice tuffs. It may consist purely of fragments of pumice, or a certain amount of finer volcanic ash may be present. Near the Green Lake it is a bluish-yellow clay, mostly covered with rounded pumice stones. Logs of trees are lyinig about here and there, while some dead stumps are still standing.

Tutu (Coriaria sai mentosa) scrub covers considerable areas in the crater, occupying land of the very poorest and driest king. It is a more or less open formation, and consists principally of rounded Coriaria shrubs 3–5 m. tall. Near the Green Lake shrebby Metrosideros villosa, 1–2 m. in height, occurs. Flowering-plants ½ m. tall were observed on Naked Spur.

The ground is quite bare in places; elsewhere the vegetation in scanty. Scirpus nodosus, Microtis unifolia, Scævola gracilis, Gnaphalium luteo-album, Ophioglossum coriaceum, and Imperata Cheesemam are perhaps the plants most commonly met with, while near the Green Lake Lycopodium cernuum adn L. volubile are abundant. The last plant is much sought after by goats, which eat it down close to the ground.

In a small gully from which steam was escaping in several places were found Dryopteris parasitica and D. setigera, whilst Nephrolepis exaltata occured on warm ground at the foot of some cliffs.

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(c.) Pohutukawa (metrosideros) Forest.—Metorosideros villosa in the eruption area is a slender tree, usually with several stems springing from the same root; the lower branchlets are dead, and the foliage chiefly borne at the top; height, 8 m.; circumference of stems, –46 cm.]

On the inner crater ridge the forest is composed almost exclusively of metrosideros saplings 8 m. tall, growing close together. The groud is quite bare of vegetation nearly everywhere, but dead leaves and sticks are thickly strewn about. Where there is a break in the forest, Ageratum conyzoides, Oplismenus undulatifolius, &c., are found.

The gulies between this ridge and Mount Campbell are filled with ferns, chiefly young Cyathea Milnei and Pteris comans.

On the flat ground at the base of Mounmoukai Coriaria sarmentosa, Cooprosma acutifolia, Myoporum lætum, and Cyathea Milnei occur with Metrosideros villosa, while Cyclophorus serpens is occasionally present as an epiphyte. The undergrowth whe present contains Polystichum aristatum, Pellæa falcata, and Nephrolepis cordifolia.

5. Introduced Formations.

I apply the term “introduced” to the three meadows occurring in the Kermadec Islands because in each the principal plant is an imported species. In all cases these meadows occupy ground cleared of its original scrub or forest by man. The soil, unlike that of the “young” formations, was at the time of the clearing of the forest in a fit statse to receive new plants, and the existence of these fromations is, in my opinion, good evidence of the superiority of plants of widespread occurrence over indigenous plants in a confined area where competition has not been keen. But climatic conditions on Sunday Island favour the growth of forest, so that, though the newcomers quickly take possession of the ground, they must eventually retreat before the encroaching forest. With regard to ground occupied by the young formations, it is in its nature so barren that indigenous species of trees (metrosideros villosa, Myoporum lætum, Coriaria sarmentosa) grow as fast as introduced plants; hence the latter suffering from the shade of the former, have not a chance of monopolizing the ground. In any case, if let alone forest will ultimately cover both areas, with introduced plants as unimportant members only.

(a.) Ageratum Madow.—Ageratum meadow occupies all the clearings in the forest in Denham Bay. The chief plant is Ageratum conyzoides, which covers the ground to a height of about ½ m. The leaves are light green or yellowish-green; lilac-blue flowers are produced profusely throughout the year. All other plants in this formation occur more or less sporadically. The following are most commonly met with: Dryopteris parasitica, Kyllinga brevifolia, Carex lucida, Sida rhombifolia, Vinca rosea, and Anthoxanthum odortum.

(b.) BLuffalo-grass (Stenotaphrum) Meadow.—Buffalo-grass meadow occurs on the Terraces, on Low Flat and the adjoining crater-ridge, and in one place on the east coast. It forms a dense impenetrable mass, ½-2 m. high, wiht an uneven surface. It ha taken almost entire possession of the ground, as only a few other plants struggle for a bare existence amongst it.

So much do the culms of the buffalo-grass (Stenotaphrum glabrum) intertwine, and so dense in the resulting mass, that it is only with the greatest difficulty that one can scramble over it, while walking through it is quite impossible. It is shunned by every one who has been unfortunate enough

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to make its acuaintance, and even goats keep clear of it, tempting though its young fresh green leaves may look. Underneath the surface is a mass of rottig leaves, damp and evil-smelling. Seedlings of other plants have little chance of growing to any size, being soon smothered by the relentless buffalo-grass. Though thousands of berrises yearly fall from the plams (Rhopalostylis Baueri) which the grass has surrounded, there are no young plants, but rotting berries may be found in abundance.

Over parts of the Terraces one plant seems to flourish in spite of the buffalo-grass. I refer to Ipomæa plamata, whose long stems penetrate the dense matted grass, and, reaching the open air, trail along the surface, bearing leaves and flowers in profusion.

Certain other plants are found in the formatio. Chief among these are young Myoporum lætum and Metrosideros villosa trees, the forerunners of a forest which will ultimately replace the buffalo-grass.

A few plants of Homolanthus polyandrus, with their upper leaves much torn by wind, are protected from goats by the very grass which almost smothers them. The leaves are large, and have much purplish-red about them; laminæ 19.5x21 cm.; petioles 21 cm. and 26.5 cm. respectively.

Spaces more or less clear of buffalo-grass are occupied by such plants as Scirupus nodosus, Ageratum conyzoides, Mariscus ustualtus, Macropiper excelsum major, and Hypolepis tenuifolia.

On Low Flat buffalo-grass meadow reches the coast, and, partly covering some sand-dunes, includes such plants as Ipomæa pes capræ, Cenchrus calycualtus, Scævola gracilis, and Pteridium esculentum replaces buffalo-grass.

The buffalo-grass (Stsenotaphrum glabrum) does not spread into the forest, as want of light effectively stops progress in that direction. Like Ageratum conyzoides, it takes possession of the ground quicker than forest, yet there is little doubt that now, after twenty years' occupation, the grass is being driven back by forest. Young Metrosideros and Myoporum trees are springing up everywhere; Cordyline termnalis ±2 m. tall, with wind-torn yellow or yellowish-green leaves, is also growing thickly in places. Where these plants, especially metrosideros, are growing close together the buffalo-grass is dying; it is, indeed, being killed by the shadow of the trees.

(c.) Beard-grass (Polypogon) Meadow.—Macauley Island, once covered with Myoporum lætum and Marisus ustulatus (see ante, p. 131) is now clothed only with a closely cropped and scanty mantle of grasses. No trace of the original scrub remains. The soil is formed of ashes and scoria resting on pumice. It is exposed to all winds, and consequently, except in wet weather, is usually in a parched state. At the north-east corner of the island, where the ground is a loose scoria, there is no vegetation at all.

The grass is everywhere closely cropped by the thousands of goats now roaming about the island. Nowhere is it more than a few centimeters in height. Three species were collected: Polypogon monspeliensis (beard-grass) appeared to be most plentiful, though Festuca bromoides and Danthonia pilosa were abundant. A few other plants only were noticed among the grass—Oxalis corniculata, Cotula australis, and Wahlenbergia gracilis with peduncles about 10 cm. high.

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VII. Geographical Distribution.

(a.) The Species.

In the list of pteidophytes and spermophytes given in this paper 114 species are admitted as indigenous to the Kermadec Islands. Of these, 76, or 67 per cent., are flowering-plants, and 38, or 33 per cent., ferns and fern-alles.

The 114 species are referred to 88 genera, belonging to 42 families. The flora is thus most fragmentary, and characteristic of oceanic islands, whither plants are accidentally carried by ocean and air currents, and possibly other means. Twelve species, or 11 per cent., are endemic. The age of the island, therefore, will not be so great as that of Norflok Island or Lord Howe Island, where the proportion of peculiar forms is about one-fifth and one-fourth respectively.

The relations of the Kermades Islands plants to those of Lord Howe Island, Norfolk Island, New Zealand, Australia, and Polynesia are expressed in the following table:-

Per Cent. H., N. New Zealand. Australia. Polynesia. Endemic.
6 7 4
14 16 2
2 2 1
1 1 1
1 1 1 1
3 3 3 1
4 5 5 5
3 4 4 1
3 3 3 1
4 5 5 5 1
3 3 3 3
10 11 11
17 19 19 19
30 34 34 34 34
68 95 78 62 12

The first column shows the percentage of the different constituents to the whole flora. The extensions of the plants to Lord Howe and Norfolk Islands (one or both) are shown in the second column. “Australia” means the eastern portion of the continent and Tasmania. Polynesia includes New Caledonia.

In the four central columns of the above table every species is taken into account. If a species is endemic it is counted under the headings in which its nearest related species falls. Thus Poa polyhylla, being closely allied to P. anceps, a peculiar New Zealand form, is included in the 16 shown under “New Zealand,” and, as this number stands in a row by itself, it signifies that 16 species of Kermadec Islands plants, or 14 per cent. of the flora, are identical with or related to endemic New Zealand forms. Similarly Rapanea kermadecensis, which is related to R. crassifolia, occurring in Norfolk Island and Australia, is the species represented by the fifth row. The seventh row of figures shows that five species of Kermadec Islands plants are identical

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with species occurring in Lord Howe and Norflok Islands (one or both), Australia, and Polynesia, but not in New Zealand. The last row shows that 34 species, or 30 per cent. of the flora, are found in all four regions named in the table; and so on. The number of species extending to each of the four regions is shown at the foot, whilst the total number occurring in the Kermadecs—namely, 114—may be obtained by adding together the numbers for each row.

The last column shows where the 12 endemic species are included in the table, and the following list is in the order in which they appear:-

  • Cyathea kermadecensis,

  • Imperata Cheesemani,

  • Ascarina lanceolata,

  • Homolanthus polyandrus,

  • Poa polyphylla,

  • Veronica breviracemosa,

  • Boehmeria dealbata,

  • Rapanea kermadecensis,

  • Scævola gracilis,

  • Coprosma acutifolia,

  • C. petiolata,

  • Cyathca Milnei.

The large Polynesian element represented in the above species seems to indicate that arrivals are less frequent from the north than from New Zealand.

Before going into details regarding the geographical relationships of the plants of the Kermadec Islands, a few remarks are necessary to clear the way. The figures given above include 38 ferns and fern-allies, which, on account of the lightness and abundance of the spores they produce, are of little value in estimating the amount of affinity of the flora with those of the surroundings lands. Again, I consider plants taking essential parts in the different formations are of more importance than those occuring sporadically, and sometimes having the appearance of having been introduced, but in the absence of direct evidence retained in the flora. As belonging to the latter category I should name Rumex, flexuosus, Eleusine indica, Kyllinga brevifolia, Halorrhagis erecta, Calystegia ssepium, Oxalis corniculata, Solanum nigrum, Bidens pilosa, and several others. The Australian element may be disposed of at once. and will be desregarded when considering the relationships of the plants. Of the 78 species, all but 9 are found in New Zealand, and not one Australian species does not occur in one or more of the other three regions named in the table. It is probable that no plants have reached the Kermadecs from Australia direct—a conclusion arrived at by Mr. Cheeseman after his visit to the group in 1887 (1; p. 160).

In the following remarks an endemic species is cosidered as equivalent in its distribution to its most closely allied species.

The 34 species of Kermadec Islands plants common to the four regions named in the above table need not be further considered. They include Pisonia Brunoniana, some coastal plants such as Mesembryanthemum australe, Tetraonia expansa, Apium prostratum, and Sicyos australis, 19 ferns and fern-allies, and 10 others.

As pointed out in the introduction to this paper, the Kermadec Islands form part of the New Zealand biological region. The figures given in the table leave no room for doubt on this point. To the 16 species confined to the Kermadecs and New Zealand must be added the 11 also found in Australia, making in all 24 per cent. of the flora; and assuming Lord Howe and Norfolk Islands to be part of the New Zealand region the proportion would be 47 per cent. The New Zealand species include six forest-trees (Myoporum lætum, Coriaria sarmentosa, Corynocarpus lævigata, Melicope ternata, Nothopanax arboreum, Pittosporum crassifolium), Poa polyphylla

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(end.), Veronica breviracemosa (end.), mariscus ustulatus, Lepidium oleracum frondosum, Carex Forsteri insularis, and 16 plants of leser importance, one of which is a fern.

The Polynesian element in the Kermadec Islands flora is considerable, and characterizes the group as belonging to a distinct province of the New Zealand biological region. Of the 28 species not common to all the regions under consideration, 6 extend to Lord Howe and Norfolk Islands (one or both), 9 to New Zealand, and 3 to both places. This leaves 10 purely Polynesian specieś, of which 4 are ferns (including Cyathea kermadecensis). The remaining 6 are Homolanthus polyandrus (end.), Ascarina lanceolata (end.), Scævola gracilis (end., but affinities uncertain), and 3 grasses—Imperata Cheesemani (end.), Eleusine indica, Cenchrus calyculatus. Of the 9 species extending to New Zealand, 7 are ferns, 1 is Coprosma acutifolia (end.), and the other Kyllinga brevifolia (possibly introduced). Compared with the New Zealand species, the Polynesian forms in the Kermadecs must be considered weak.

(b.) The Subtropical Islands Province.

It remains to point out the relation of the Kermadec Islands plants to those of Lord Howe and Norfolk Islands. Excluding the 34 widely spread species, 34 Kermadec Islands plants are found in Lord Howe and Norfolk Islands (one or both). Of these, 22 occur in New Zealand, 6 in Polynesia, and 3 in both of these regions. The remaining 3 species are confined to the three groups of islands forming the northern province of the New Zealand region. They are Rhopalostylis Baueri, Rapanea kermadecensis, and Boehmeria dealbata. These plants enter largely into the forest on Sunday Island, and, while Rhopalostylis Baueri is found on Norfolk Island, the others are endemic, but closely related to Norfolk Island forms. The New Zealand species include Coprosma petiolata (end.), 4 ferns, Scirpus nodosus, Heleocharis acuta, Microtis unifolia, Parietaria debilis, Peperomia Endlicheri, and 12 others not taking prominent parts in the plant formations of Sunday Island. The 6 Polynesian species are Metrosideros villosa, Ipomæa pes capræ, Canavalia obtusifolia, 2 ferns, and Panicum sanguinale microbachne. Those common to both New Zealand and Polynesia are Melicytus ramiflorus, Macropiper excelsum, and Diplazium japonicum.

The greater part of the vegetation on Sunday Island is thus composed of plants extending to (or closely related to species in) Lord Howe and Norfolk Islands (one or both), and, of these, Metrosideros villosa, Rhopalostylis Baueri, Rapanea kermadecensis, Boehmeria dealbata, Ipomæa pes capræ, and others do not occur in New Zealand. Dr. Cockayne has drawn my attention to the large proportion of Norfolk Island forms in the New Zealand species found in the Kermadecs. Of the New Zealand plants on Sunday Island, 54 per cent. are also found in Norfolk Island, but of the total number of species in New Zealand only 8 per cent. extend to Norfolk Island, It is probable, then, that a number of the Kermadec Islands plants occurring in both Norfolk Island and New Zealand arrived from Norfolk Island direct; but the above figures do not express the relations quite correctly, as the whole of the New Zealand flora is made the basis of the calculation, instead of the North Island, whence only New Zealand plants could be expected to migrate to the Kermadecs.

No doubt climate determines which species shall establish themselves; hence in Lord Howe, Norfolk, and Sunday Islands, which are in nearly the same latitude, a large number of the species (48 to 60 per cent.) in each

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island are identical with or representative of species in the other two islands. I therefore consider the three groups of islands to form a natural province or subregion.

The numerical distribution of the plants of the Kermadec, Norfolk, and Lord Howe Islands is shown in the following tables:— Kermadec, 114 Species.

Per Cent. New Zealand. Australia. Polynesia. N., L.H.
8 9 2
1 1 1
19 20 5
6 7 7 3
26 30 30 19
6 8 8 5
34 39 39 39 34
96 78 63 69
Norfolk, 208 Species.
Per Cent. New Zealand. Australia. Polynesia. K., L.H.
5 10 4
13 27 6
7 15 5
3 7 7 4
19 40 40 25
26 54 54 29
26 55 55 55 45
117 176 126 121
Lord Howe, 212 Species.
Per Cent. New Zealand. Australia. Polynesia. K., N.
5 11 5
23 48 6
8 17 4
1 3 3 2
17 37 37 19
23 48 48 25
23 48 48 48 40
105 181 110 101

As before, the first column shows percentages, and every species is taken into account in the three central columns. The last column shows the

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extensions of the plants of each island to the other two islands whose plants are tabulated.

The figures for Lord Howe and Norfolk Island plants are compiled from the lists published by Mr. W. B. Hemsley (9; p. 221) and Mr. J. H. Maiden (13 and 14), and corrected with the further notes by Mr. Maiden in the Proc. Linn. Soc. N.S.W.

A comparison of the three tables reveals certain facts which I think can be explained by the geographical position of the islands and the known direction of prevailing winds and ocean-currents in this portion of the Pacific Ocean.

The proportion of New Zealand species decreases from east to west, while there is a corresponding increase of Australian forms in the same direction. In all cases the Polynesian element is not so important as that of either New Zealand or Australia, the proportion of Polynesian plants not extending to either of the latter regions being small. The large number of Australian plants on Lord Howe and Norfolk Islands is due to the nearness and extent of coast-line of the continent in a north-and-south direction, and consequently plants have had frequent chances of reaching, and now outnumber the New Zealand species in, these islands. The tables show that, of the 27 and 48 purely Australian forms in Norfolk and Lord Howe Islands respectively, only 6 in each case extend to the other island or the Kermadecs. It is evident that the Australian species are more of the nature of stragglers which have accidentally found their way across the ocean.

The endemic species appear to be more closely allied to New Zealand and New Caledonian than to Australian forms. Lord Howe and Norfolk Islands are in the line of migration of plants and animals (8; p. 397: 12; p. 19) between Malaya and New Zealand.

In considering the distribution and relationships of the floras of Lord Howe, Norfolk, and the Kermadec Islands certain species may be disregarded—for instance, all the sporiferous plants, and a host of Australian and other species belonging to widely distributed genera. The remaining genera are here enumerated for the purpose of showing the true affinities of these insular floras.

Araucaria excelsa, R. Br., of Norfolk Island, resembles A. Cookii, R. Br., of New Caledonia, and A. Cunninghamii, Ait., of Queensland and New South Wales.

Pandanus Forsteri, C. Moore and F. v. Muell., in Lord Howe Island, is allied to a Malayan species (P. odoratissimus).

Freycinetia and Cordyline are Oriental genera reaching as far as Queensland and New South Wales in one direction, and Norfolk Island and New Zealand in another.

Howea, a genus of two species confined to Lord Howe Island, is apparently related to Australian and Malayan forms. Clinostigma contains one species in Lord Howe Island, and three or four in New Caledonia and Samoa.

Rhopalostylis includes two species—one in New Zealand, the other confined to Sunday and Norfolk Islands. Hedyscepe, monotypic in Lord Howe Island, is related to Rhopalostylis.

Phormium is confined to New Zealand and Norfolk Island.

The tropical genus Boehmeria has three closely allied endemic species in Lord Howe, Norfolk, and the Kermadec Islands (one in each group), but does not extend to either New Zealand or Australia.

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Colmeiroa, a monotypic genus confined to Lord Howe Island, is allied to the endemic monotypic Carpodetus of New Zealand.

Carmichaelia, a characteristic New Zealand genus of nineteen species, has a twentieth in Lord Howe Island. Streblorhiza, endemic in Norfolk Island, is related to Carmichaelia.

Homolanthus is a Malayan and Polynesian genus. It extends down the east coast of Australia, to New Caledonia and Lord Howe Island, and in a peculiar species to the Kermadecs.

Corynocarpus contains two species—one in New Zealand and the Kermedecs, the other in New Caledonia and the adjacent islands.

The Norfolk Island endemic genus Ungeria is related to Reevesia of the Oriental region.

Melicytus has four species in New Zealand, one of which extends to Norfolk and Sunday Islands and Eua (a small islet in the Tonga Group).

Acicalyptus has one species in Lord Howe Island, another in Fiji, and three in New Caledonia.

Metrosideros is a Malayan and New Zealand genus. The Polynesian species, M. villosa, extends to New Caledonia, Lord Howe Island, and the Kermadecs.

Meryta has ten species in New Caledonia, two in Norfolk Island, one in New Zealand, and two or three in the Pacific islands.

Negria, a monotypic genus confined to Lord Howe Island, is allied to Rhabdothamnus, monotypic in New Zealand, and both are near Coronanthera of New Caledonia.

Coprosma, a characteristic New Zealand genus, is represented in Lord Howe Island by three species, in Norfolk Island by three species, and in the Kermadecs by two. C. petiolata of the Kermadecs is closely allied to C. Baueri of Lord Howe Island, Norfolk Island, and New Zealand.

Lagunaria (scarcely distinct from Hibiscus) is monotypic in Queensland, Lord Howe and Norfolk Islands. Besides this genus only three others strictly Australian extend to Lord Howe Island. These are Smilax, Notolæa, and Westringia, each represented by one species, of which the Notolæa is peculiar. It should be pointed out that the most characteristic Australian genera are eiter entirely absent, or represented by one or two species only. For instance, Acacia, Eucalyptus, Melalauca, Leucopogon, Grevillea, and Hakea together contain about 900 species, and form a large part of the vegetation in the eastern portion of the continent, yet only two species (Melaleuca ericifolia and Leucopogon Richei) have found their way to Lord Howe Island.

The floras of the three islands under consideration are fragmentary, but on account of the isolated positions of the islands this would be expected. Further, the geological structure does not suport the supposition that the islands are the remnants of a large land-mass, nor does there appear to be a plant formation on any one of them that one might suspect to be a fragment of a once more extensive forest. At the same time it is impossible to believe that all the plants populating these islands have crossed the wide stretches of ocean now separating them from the nearest land-masses.

In view of the presence of the genera above enumerated, of the community of genera and species of each island with the other two, and the relation of the same to those found in the three adjacent biological regions as expressed in the foregoing tables, the following are suggested in explanation of the origin of these insular floras.

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The floras of Lord Howe and Norflolk Islands are fragments of the larger one which migrated from Malaya by this way to New Zealand, received from the continental bridge stretching between New Caledonia and New Zealand, before it disappeared beneath the surface of the sea; together with a number of Australian forms which have arrived from time to time across the intervening space of ocean.

The Kermadec Islands have received their plants by transoceanic migration mainly from New Zealand, but also from Norfolk Island and Polynesia (see 1; p. 163). They are younger than Norfolk or Lord Howe Islands, but are attached to them because of the large community of species of plants with, and the possession of genera and species characteristic of, those islands.

The three groups of islands possess insular floras, are properly included in the New Zealand biological region, and together form a subregion for which is proposed the name “subtropical islands province,” in contradistinction to Dr. Cockayne's “subantarctic islands province.”

(c.) The Formations.

On an oceanic island which depends for its stock of plants on accidental migrations the flora is necessarily of a fragmentary character, and different forms arriving from various directions compete with one another for the ground. Thus a plant taking a minor part in a formation in the land of its origin may in its new home be able to compete successfully with the plants from other countries with which it comes in contact, and take a leading part in some formation. Where a small island in mid-ocean, such as Sunday Island, has received its plants from two or three equidistant fully stocked areas containing widely different assemblages of plants, one might expect the resultant plant formations to be new combinations of species. The affinities of the two most characteristic of the Sunday Island plant formations—forest and gravel flat—will be considered briefly here. In both New Zealand, Polynesian, and Lord Howe-Norfolk Island forms mingle in plant-communities which from the diverse origin of their constituents are peculiar.

The three principal plants of the gravel flat in Denham Bay are Ipomæa pes capræ, Mariscus ustulatus, and Scirpus nodosus. The first is a common shore-plant in most tropical countries; it occurs in Lord Howe and Norfolk Islands, but not in New Zealand. Mariscus ustulatus is confined to New Zealand; whilst Scirpus nodosus is found in New Zealand, Lord Howe and Norfolk Islands, but not in Polynesia.

Metrosideros villosa, the principal forest-tree on Sunday Island, is distributed throughout Polynesia, from New Caledonia to Tahiti and the Sandwich Islands, and also on Lord Howe Island. Should it on any of the Pacific islands take a leading part in a forest, there might be a superficial resemblance between this formation and the forest on Sunday Island; but the principal species of trees associated with it could not be identical with more than one or two of the Sunday Island. Rhopalostylis Baueri, an important member of the Sunday Island forest, occurs elsewhere on Norfolk Island only. Rapanea kermadecensis and Boehmeria dealbata are peculiar to the Kermadecs, but closely related to Norfolk Island plants. Corynocarpus lævigata, Myoporum lætum, Nothopanax arboreum, Melicope ternata, and Pittosporum crassifolium are endemic New Zealand species. The two species of Cyathea, and Ascarina lanceolata, while not occurring in

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New Zealand, may possibly be identical with Polynesian forms. Melicytus ramiflorus occurs in Norfolk Island, New Zealand, and Eua (Tonga Group). Coprosma acutifolia is endemic.

In view of the distribution of the arborescent forest-plants of Sunday Island, it follows that the forest as a formation is peculiar, contains some Norfolk Island and New Zealand forms, but most probably has greatest affinities with forest formations in certain of the islands of Polynesia. Mr. Cheeseman records (3; p. 267) that in Rarotonga Metrosideros villosa and Ascarina lanceolata grow in company.

(d.) Dispersal.

Ocean-currents have probably been the means of transporting to the Kermadec Islands the seeds of a large number of the plants now found there. The nature of the material cast up on the shores of Sunday Island points to the south or south-west as the direction from which the strongest and most frequent reach the group.

Several kauri (Agathis australis, Salisb.) logs, some bearing brands of New Zealand firms, are lying on the shores of Sunday Island, and on the north coast is a balk of Oregon pine supposed to have formed part of the cargo of the “Elingamite,” wrecked on the Three Kings Islands in 1903. Again, during the months of July to October, 1908, when strong westerly winds prevailed, a large amount of seaweed was cast up in Denham Bay. Mr. R. M. Laing, M.A., BSc., has supplied me with the following names of algæ collected by me on the beaches on Sunday Island:—

  • D'Urvillæa antarctica,
  • Carpophyllum maschalocarpum,

  • Hormosira Banksii,

  • Zonaria Turneri.

All the specimens appeared to have come long distances, some having small barnacles (Lepas) attached, and I do not consider any of the above species are to be found living in Sunday Island waters. According to Mr. Laing, they are all New Zealand and south-east-Australian forms.

It is evident that a strong ocean-current flows from New Zealand in a north-easterly direction; and this, in my opinion, is sufficient to account for the preponderance of New Zealand forms in the flora of the Kermadec Islands.

Seeds attached to logs or trees would have a greater chance of crossing wide spaces of ocean and arriving in a fit state for germinating than if they merely floated on the surface of the water. Forest-plants especially would rely on this mode of transportation. Of nineteen kinds of seeds experimented on, I found two only floated for any length of time in salt water. These were Ipomœ pes caprœ and Canavalia obtusifolia, two shore-plants widely distributed in tropical regions.

The large proportion of sporiferous plants, amounting to one-third of the flora, is suggestive of air-currents being an important factor in stocking remote oceanic islands with plants. It is a significant fact, too, that Metrosideros villosa, which produces an abundance of very light seeds, is widely distributed in Polynesia, and reaches some of the most distant and isolated islets. This plant is the principal tree on Sunday Island.

Birds have possibly assisted the migration of a number of plants to the Kermadecs. The tui (Prosthemadera novœ zealandiœ), a fruit-eating bird, is very common on Sunday Island; and a pigeon was once found there, but has since been exterminated by cats introduced by the settlers who from time to time have made their home on Sunday Island.

– 157 –

The following plants have berries or other succulent fruits, and some of them the tui has been observed to eat:—

  • Melicytus ramiflorus,

  • Rapanea kermadecensis,

  • Myoporum lœtum,

  • Coprosma petiolata,

  • C. acutifolia,

  • Ascarina lanceolata,

  • Scœvola gracilis,

  • Rhopalostylis Baueri,

  • Corynocarpus lœvigata.

The experiment was tried of floating fruits of the above plants in seawater, but with most disappointing results: some of the fruits sank immediately, and none floated for more than a few days.

The harrier (Circus gouldi) is a regular annual visitor to Sunday Island, and a few grey ducks (Anas superciliosa) were seen at different times. These birds are possibly the means of carrying small seeds to the islands.

VIII. List of Indigenous Pteridophytes and Spermophytes.

Hymenophyllaceæ.

Trichomanes venosum, R. Br.

Epiphyte in wet forest, Sunday Island.

New Zealand, Australia.

Trichomanes humile, Forst. f.

Damp banks and fallen Cyathea trunks in wet forest, Sunday Island.

Norfolk Island, New Zealand, Australia, Polynesia, Malaya.

Hymenophyllum demissum (Forst. f.), Sw.

Epiphyte and on ground in wet forest, rare in dry forest, Sunday Island.

New Zealand, Polynesia, Malaya.

Hymenophyllum flabellatum, Lab.

Epiphyte in wet forest, Sunday Island.

Lord Howe Island, New Zealand, Australia, Samoa.

Cyatheaceæ.

Cyathea Milnei, Hook.

Hitherto only one species of Cyathea has been recognised from Sunday Island. Previous collectors gathered fronds of this, which, though not so tall, is far less abundant than the following species, and in references to C. Milnei both species have been confused. Thus the statement made by Mr. Cheeseman (1; p. 154)—“A fine tree-fern (Cyathea Milnei) which is peculiar to the islands is also very plentiful, especially towards the tops of the hills, and in all the ravines. It is often 50 or 60 feet in height, and is thus quite equal in stature to our Cyathea medullaris, which it much resembles”—is wholly true of Cyathea kermadecensis, but entirely inapplicable to C. Milnei. A full description of the latter species will therefore be given here.

Trunk stout, short, 2–8 m. tall; rough with the broken-off bases of old stipes, and clothed at the top with hanging withered fronds; base of aerial rootlets conical, –80 cm. in diameter.

Fronds numerous, horizontally spreading, 2.5–4 m. long, 1.2 m. broad, coriaceous, upper surface hard and shining, dark green, paler beneath. Stipes stout, clothed at the base with copious linear brown scales; under

– 158 –

surface with close hard tubercles; rhachides and costæ green, slightly grooved above, asperous chiefly on; the under-surface, sparingly covered with yellowish-brown deciduous wool intermixed with membranous scales.

Primary pinnæ 45–60 cm. long, –23 cm. broad, oblong-lanceolate, abruptly terminating in an attenuated point; secondary pinnæ 11–12.5 cm, long, 2–2.5 cm. broad, linear-oblong, falcate, narrowing gradually to an attenuated deeply serrated point; deeply pinnatifid or pinnate. Segments 12–15 mm. long, 4 mm. broad, oblong, falcate, acute, obscurely crenateserrate, sometimes the distal portion distinctly serrate, margins slightly recurved, under-surface often scaly pubescent; veins forked, free.

Sori copious, rather large; 0.8–0–9 mm. in diameter, nearer the costule than the margin. Indusium membranous, splitting irregularly, persistent.

Forest (most abundant in dry forest), pohutukawa forest (crater), Sunday Island.

Endemic.—The fronds closely resemble those of C. medullaris of New Zealand, Australia and the Pacific islands.

Cyathea kermadecensis, n. sp.

Caudex gracilis, 15–20 m. altus. Frondes 3–4 m. longæ, –90 cm. latæ, bi-tripinnatæ, subcoriaceæ v. fere membranaceæ, flaccidæ Stipites rhachidesque graciles, basi squamis fuscis lineariis vestiti, supra alte canaliculati, virides, lana flavofusca et squamis lineariis dense vestiti, subtus subasperi, fusci, lana decidua et squamis membranaceis. Pinnæ 35–45 cm., longæ, –14 cm. latæ, oblongo-lanceolatæ, acutæ; pinnulæ 60–70 mm longæ, 15–18 mm. latæ, lineario-oblongæ, acutæ, profunde pinnatifidæ; segmentæ, 8–9 mm. longæ, 3 mm. latæ, oblongæ, falcatæ, obtusæ, integræ v. crenulatæ. Sori copiosi, parvi, 0.5–0.6 mm. lati. Indusium membranaceum, fimbriato-lacerum, persistens.

A magnificent species, with a tall, slender trunk, –20 m. high; the base composed of aerial rootlets, reaching 3 m. or 4 m. from the ground, where it may be 1–2 m. in diameter. Fronds fall away when they wither, leaving a clean scar; thus the upper portion of the trunk is comparatively smooth. The diameter, 1.5 m. from the top of a trunk 11 m. tall, was only 11 cm.

Fronds numerous, the stipes forming an angle of 100°–120° with the top of the trunk, 3–4 m. long, 70–90 cm. broad, 2–3-pinnate, subcoriaceous or almost membranous, flaccid, dull green above, paler beneath. Stipes slender, base clothed above and on the sides with copious linear brown scales; stipes, rhachides, and costæ deeply grooved above and slightly on each side, green above, brown below, upper surfaces densely covered with yellowish-brown wool intermixed with small linear scales, undersurfaces slightly asperous, sparingly covered with yellowish-brown deciduous wool and membranous scales.

Primary pinnæ 35–45 om. long, –14 cm. broad, oblong-lanceolate, acute or acuminate; secondary pinnæ 60–70 mm. long, 15–18 mm. broad, linear-oblong, acute or acuminate, obscurely falcate, deeply pinnatifid. Segments 8–9 mm. long, 3 mm. broad, oblong, falcate, obtuse or subacute, entire, or finely crenulate, or the fertile segments lobulate; costules scaly pubescent; veins forked, free.

Sori copious, small, 0.5–0.6 mm. In diameter, nearer the costule than the margin. Indusium membranous, splitting irregularly, persistent.

Forest (chiefly in wet forest), Sunday Island.

Endemic. Apparently closely allied to some Polynesian species.

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Polypodiaceæ.

Dryopteris setigera (Bl.), O. Ktze.

I have a specimen in which the costa, of one of the primary, pinnæ divides. Length from rhachis to fork, 6.7 cm.; of the two branches of the pinna, 14 cm. and 17 cm.

Dry forest, swamp (a few plants, fronds 50 om. long); near fumaroles (crater), Sunday Island.

Norfolk Island, Australia, Polynesia, Malaya.

Dryopteris parasitica (L.), O. Ktze.

Dry forest, swamp (a few plants), Ageratum meadow, near fumaroles (crater), Sunday Island.

Norfolk Island Lord Howe Island, New zealand, Australia, Tonga, tropics.

Dryopteris glabella (A. Cunn), C.-Chr.

Rhizome small, short, tufted; fronds perfectly glsbrous; lower basal secondary pinnæ of lowest primary pinnn;s usually much longer than the rest.

Forest, Sunday Island.

New Zealand, Australia, Polynesia.

Polystichum aristatum (Sw.), Pr.

Dry forest, swamp, pohutukawa forest (crater), Sunday Island.

Norfolk Island, Australia, Tonga, tropics.

Nephrolepis exaltata (L.), Schott.

Dry forest (Denham Bay), on warm ground near fomaroles (Denham Bay, crater), Sunday Island.

Australia, Tonga, tropics.

Nephrolepis cordifolia (L.), Pr.

Forest, cliffs (crater), pohutukawa forest (crater), Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, tropics.

Diplazium japonicum (Thbg.), Bedd.

Forest, Sunday Island.

Norfolk Island, New Zealand, Eliji, tropics.

Asplenium caudatum, Forst. f.

Forest, Sunday Island.

Polynesia, tropics.

Asplenium obtusatum, Forst. f.

Coastal rocks, Sunday Island. Herald Islets. Cliffs, Macauley Island. French Rock.

Norfolk Island, Lord Howe Island; New Zealand, Australia, Polynesia, islands of the Southern Ocean.

Asplenium lucidum, Forst. f.

Dry forest, Sunday Island. Scrub, Meyer Island. Ravines in Macauley Island.

Lord Howe Island, New Zealand, Australia, Polynesia.

– 160 –

Var. Lyallii, Hook.—This form is intrmediate between acutely pinnate states of A. lucidum (or A. obtusatum) and the less-divided forms of A. Shuttleworthianum.

Coastal rocks, Sunday Island.

Asplenium flaccidum, Forst. f.

Epiphyte in forest, Sunday Island.

New Zealand, Australia, Polynesia.

Variety.—Fronds oblong-lanceolate, pendulous, –60 cm. long. Epiphyte in wet forest, Sunday Island.

Asplenium Shuttleworthianum, Ktze.

A very variable species. Fronds broadly ovate, 3–4 pinnate, –50 cm. long, –25 cm. broad, coriaceous, yellowish-green, erect or pendulous. Sori copious, short. The segments are sometimes reduced to the bare costæ, expanding only to support the sori. In the typical form the secondary pinnæ are lanceolate, deeply pinnatifid or the lower part pinnate; segments linear-spathulate, divided into two or more lobes which are linear, obtuse. ± 1.5 mm. across. Sori 2–4 mm. long.

Inland rocks, Sunday Island. Scrub, Meyer Island.

Polynesia.

Variety.—Primary pinnæ ovate-Ianceolate, deeply pinnatifid above, pinnate below; the secondary pinnæ stipitate, oblong, cuneate at the base, obtuse, deeply serrate; segments linear, obtuse, the lower ones two or more lobed at the tip.

Coastal rocks, Sunday Island.

The typical form of Asplenium Shuttleworthianum appears to be derived from A. obtusatum or A. lucidum through this variety and A. lucidum Lyalli. In A. Shuttleworthianum the frond lamina is reduced to its utmost limit.

Blechnum norfolkianum (Hew.), C. Chr.

Forest, Sunday Island. Macauley Island (Cheeseman). Norfolk Island, New Zealand.

Blechnum capense, (L.), Schlecht.

Pinnæ often partly fertile and partly sterile. Sometimes the middle third only is fertile.

Forest, swamp, Sunday Island.

Lord Howe Island, New Zealand, Australia, Polynesia, widely distributed.

Doodia media, R. Br., var. Milnei (Carr), Baker.

Forest, Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, New Zealand, Australia, Polynesia (distribution of the species.)

Pellæa falcata (R. Br.), Fee.

Dry forest, pohutukawa forest (crater), cliffs (crater), Sunday Island. Macauley Island (Cheeseman).

Lord Howe Island, New Zealand, Australia, New Caledonia, Malaya.

Hypolepis tenuifolia (Forst. f.), Bernh.

Some large specimens occur at the foot of the cliffs in Denham Bay. One measured—stipe 129 cm., frond 211 cm., total length 340 cm.: another

– 161 –

—stipe 200 cm., frond 220 cm., total length 420 cm.; girth of stipe at bottom 64 mm.; length of lowest pinna 131 cm.

Dry forest, ngaio scrub, buffalo-grass meadow, landslip (Denham Bay), Mariscus slopes, Sunday Island. Ravine in Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, Malaya.

Adiantum diaphanum, Bl.

Fronds –20 cm. long, branching near the base into 2 to 5 tapering subfalcate pinnæ.

Dry forest, Sunday Island. Cliffs, Macauley Island.

Norfolk Island, New Zealand, Australia, New Caledonia, Polynesia, Asia (trop.).

Adiantum hispidulum, Sw.

Dry forest, cliffs (crater), Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, Malaya.

Adiantum affine, Willd.

Forest, Sunday Island.

Norfolk Island, New Zealand, Australia.

Pteris comans, Forst. f.

Forest, ngaio scrub, Mariscus slopes, pohutukawa forest (crater), landslip (Denham Bay), Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia.

Pteris tremula, R. Br.

Dry forest, Sunday Island. Scrub, Meyer Island. Cliffs, Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Fiji.

Histiopteris incisa (Thbg.), J. Sm.

Swamp, dry forest (rare), Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, tropics.

Pteridium esculentum (Forst. f.), Cockayne.

Dry forest, buffalo-grass meadow, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, southern regions.

Polypodium diversifolium, Willd.

P. Billardieri, Cheeseman (not R. Br.), Manual N.Z. Flora, 1013.

Forest, swamp, warm ground (Denham Bay), Sunday Island.

Norfolk Island, New Zealand, Australia, New Caledonia.

Cyclophorus serpens (Forst. f.), C. Chr.

Forest, inland rocks, cliffs (crater), epiphyte in pohutukawa forest (crater). Sunday Island.

Norfolk Island, New Zealand, Australia, New Caledonia, Polynesia.

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Ophioglossaceæ.

Ophioglossum coriaceum, A. Cunn.

Open ground in tutu scrub (crater), Sunday Island.

Norfolk Island, New Zealand, Australia.

Lycopodiaceæ.

Lycopodium Billardieri, Spring.

Epiphyte in wet forest (rare in dry forest), Sunday Island.

New Zealand, Polynesia.

Lycopodium cernum, L.

Warm ground (Denham Bay), tute scrub (crater), Sunday Island.

New Zealand, Australia, Tonga, tropics.

Lycopodium volubile, Forst. f.

Tutu scrub (crater), Sunday Island.

New Zealand, Australia, New Caledonia, Polynesia, Malaya.

Tmesipteris tannensis, Bernh.

Epiphyte on Cyathea trunks, forest; rare on damp banks in wet forest, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia.

Psilotum triquetrum, Swartz.

Dry forest, inland rocks, warm ground (Denham Bay), Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Tonga, tropics.

Typhaceæ.

Typha angustifolia, L., var. Brownii (Kunth.), Graeb.

Swamp, shores of lakes, Sunday Island.

Norfolk Island, New Zealand, Australia, trop. and temp. regions.

Gramineæ.

Imperata Cheesemani, Hack.

Cliffs, sand dunes, coastal rocks, gravel flat, tutu scrub (crater), buffalo-grass meadow, Sunday Island.

Endemic. Allied to I. exaltata, Brong.

Panicum sanguinale, L., var. microbachne (Presl.), Hack.

Buffalo-grass meadow, Sunday Island. Scrub, Herald Islets.

Norfolk Island, Lord Howe Island, Australia, Tonga, warm regions.

Oplismenus undulatifolius, Beauv.

Dry forest, pohutukawa forest (crater), Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, warm regions.

Cenchrus calyculatus, Cav.

Dry forest, buffalo-grass meadow, Sunday Island.

Australia, New Caledonia, Tonga, tropics.

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Deyeuxia Forsteri (Roem. and Schult.), Kunth.

Gravel flat, landslip (Denham Bay), Sunday Island. [Macauley Island (Cheeseman).

Norfok Island, Lord Howe Island, New Zealand, Australia.

Var. littoralis, Cheeseman.—Coastal rocks, Sunday Island. Curtis Island. French Rock.

Eleusine indica, Gaertn.

Sand dunes, cliffs, Sunday Island. Scrub. Herald Islets.

Australia, Tonga, tropics.

Danthonia pilosa, R. Br.

Gravel flat, open rocky spaces in forest, Sunday Island. Beard-grass meadow, Macauley Island.

New Zealand, Australia.

Poa polyphylla, Hack.

Coastal and inland rocks and cliffs, landslip (Denham Bay), Sunday Island. Cliffs, Macauley Island.

Endemic. Allied to P. anceps, Forst., of New Zealand.

Paspalum scrobiculatum, L.

Swamp, buffalo-grass meadow, warm ground near fumaroles (Denham Bay, crater), Sunday Island.

Norfolk Island, New Zealand, Australia, Tonga, warm countries.

Dichelachne crinita (Forst. f.), Hook f.

Open spaces in forest, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia.

Dichelachne sciurea (R. Br.), Hook. f.

Swamp, Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, New Zealand, Australia.

Cyperaceæ.

Mariscus ustulatus (A. Rich.), C. B. Clarke.

Coastal rocks, swamp, gravel flat, ngaio scrub, Mariscus slopes, landslip (Denham Bay), buffalo-grass meadow, open spaces in forest, Sunday Island. Rocks and scrub, Herald Islets. Cliffs, Macauley Island. Marisus slopes, Curtis Island.

New Zealand.

Kyllinga brevifolia, Rottb.

Ageratum meadow, Sunday Island.

New Zealand, warm countries.

Scirpus nodosus (R. Br.), Rottb.

Coastal rocks, gravel flat, landslip (Demham Bay), sand dunes, Mariscus slopes, forest, tute scrub (crater), buffalo-grass meadow, Sunday Island. Rocks, Herald Islets. Cliffs, Macauley Island. Mariscus slopes, Curtis Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, S. temp. and subtrop. regions.

– 164 –

Heleocharis acuta, R. Br.

Swamp, Sunday Island.

Norfolk Island, New Zealand, Australia.

Carex lucida Boott.

Mr. Cheeseman remarks on specimens I sent him—“It is unusual for these to have such a plentiful supply of male flowers at the top of the female spikelets.”

Ageratum meadow, Sunday Island.

New Zealand.

Carex Forsteri, Wahl.

I follow Pastor G. Kukenthal in treating C. semi-Forsteri, C. B. Clarke, as not a distinct species.

My specimens appear to differ from New Zealand ones in having all the spikelets compound, and in the possession of smooth utricles with short beaks. Mr. Maiden, of Sydney, informs me that the form is closely allied to the Norfolk Island C. neesiana, Endl. (=C. dissita, Sol., var. neesiana (Endl.), Kuk.). Under these circumstances I feel justified in giving it a varietal name.

Var. insularis, n. subsp.—Spicæ 4–10, compositæ; superiores approximatæ, subsessiles, v. breviter pedunculatæ; inferiores pedunculis longis rectis; terminales omnino v. partim masculæ, reliquæ, feminæ, basi masculæ. Perigynia elliptico-ovata, membranacea, rostrata breviter bifida, venis multis obscuris.

Coastal and inland rocks, ngaio scrub, forest, Mariscus slopes, Sunday Island. Ravines in Macauley Island.

New Zealand (distribution of species).

Palmæ.

Rhopalostylis Baueri (Hook. f.), Wendl. and Drude.

On the hillside above Denham Bay is a plant with variegated leaves. Most of the leaves have among the green pinnæ several of a light-yellow colour.

Spadix about ½ m. long; spathes 3. Flowers from November to April. Ripe fruit chiefly from April to September. Fruit globose, or broadly oblong, –16 mm. long.

Forest, Sunday Island.

Norfolk Island.

Juncacceæ.

Juncus effusus, L. (J. polynathemus, Buch.).

Swamp and damp ground (Denham Bay), Sunday Island.

New Zealand, Australia, cosmopolitan.

Juncus pauciflorus, R. Br.

Edge of swamp, Sunday Island.

New Zealand, Australia.

Orchidaceæ.

Microtis unifolia (Forst. f.), Rohb.

Open ground in tutu scrub (crater), Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia.

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Acianthus Sinclairi, Hook. f.

Forest, Sunday Island.

New Zealand.

Piperaceæ.

Macropiper excelsum (Forst. f.), Miq., var. major, Cheeseman.

Flowers April to October. Ripe fruit October to February.

Forest, ngaio scrub, buffalo-grass meadow, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, S. Polynesia.

Peperomia Endlicheri, Miq.

Two spikes with the distal ends inverted, and bearing flowers on their inner as well as their outer surfaces, were observed on plants growing among coastal rocks on Sunday Island. It occurred to me that these anomalous spikes might give some clue as to the origin of the spicate inflorescence; and its derivation from a cup-shaped receptacle by elongation and eversion is suggested.

Coastal and inland rocks, also epiphytic on tree (forest), Sunday Island. Norfolk Island, Lord Howe Island, New Zealand.

Chloranthaceæ.

Ascarina lanceolata, Hook. f.

Floweres unisexual, a male and a female in the axil of a broadly ovate, acute bract, and with a smaller bracteole on each side. Male flower a single anther, sessile, oblong, 3 mm. long, 2-celled, dehiscing longitudinally on the outer margins. Female flower placed within the anther, which falls away after dehiscing; ovary sessile, ovate, 1.5 mm. long; stigma sessile, broad.

Fruit crowded on compound spikes, several of which are usually together on the branches below and among the leaves. Drupe oblong, indehiscent, 3 mm. long, 2 mm. in diameter, white with irregular longitudinal markings of purplish-black. Exocarp succulent, exuding a purple juice when crushed. Putamen ovoid, compressed, chestnut-brown, 1.5 mm. long.

Flower June to September. Ripe fruit January to May.

Wet forest, Sunday Island.

Endemic. (According to Mr. Cheeseman (4; p. 598), this species or a very close ally is found in Fiji, Samoa, and Rarotonga.)

Urticaceæ.

Boehmeria dealbata, Cheeseman.

Seeding. Hypocotyle filiform, terete, whitish, 1 cm. long. Cotyledons orbicular, apex truncate or slightly indented, light green, 1.5 mm. in diameter. Stem erect, minutely hairy, ± 2 cm. to first leaves, reddish-green. First leaves ovate, acute, entire, light green small, petiole 7 mm., lamina 9 mm. long. Second leaves broadly ovate, acute, obscurely serrate, green on both sides, petiole and principal veins reddish-green, minutely hairy; laminæ 17 x 10 mm., 22 x 13 mm.

Forest, landslip (Denham Bay), Sunday Island. Ravine in Macauley Island.

Endemic. Closely allied to B. australis, Endl., of Norfolk Island, and B. calophleba, C. Moore and F. Muell., of Lord Howe Island.

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Parietaria debilis, Forst. f.

Coastal rocks, Mariscus slopes, Sunday Island. Scrub, Herald Islets. Macauley Island (Cheeseman). Mariscus slopes, Curtis Island. French Rock.

Norfolk Island, Lord Howe Island, New Zealand, Australia, temp. and trop. regions.

Polygonaceæ.

Rumex flexuosus, Sol.

Ageratum meadow, Sunday Island.

New Zealand.

Chenopodiaceæ.

Rhagodia nutans, R. Br.

Coastal rocks, Sunday Island. Herald Islets. Mariscus slopes, Curtis Island.

New Zealand, Australia.

Nyctaginaceæ.

Pisonia Brunoniana, Endl.

Forest, Sunday Island. Scrub, Meyer Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, Malaya.

Aizoaceæ.

Mesembryanthemum australe, Sol.

Coastal rocks and cliffs, inland cliffs, Sunday Island. Herald Islets. Macauley Island. Curtis Island. French Rock.

Lord Howe Island, New Zealand, Australia, S. Polynesia.

Tetragonia trigyna, Banks and Sol.

Cliffs on the north side of Sunday Island (Cheeseman).

Lord Howe Island and Australia (T. implexicoma, Hook. f.), New Zealand.

Tetragonia expansa, Murr.

Coastal rocks, gravel flat, Sunday Island. Herald Islets. Macauley Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, S. America.

Cruciferæ.

Cardamine stylosa, D.C.

Macauley Island (Cheeseman).

New Zealand, Australia.

Lepidium oleraceum, Forst. f., var. frondosum, Kirk.

Mariscus slopes, Curtis Island.

New Zealand.

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Pittosporaceæ.

Pittosporum crassifolium, A. Cunn.

Young leaves covered with white tomentum. Flowers dark red, hermaphrodite, produced throughout most of the year. Fruiting peduncles erect, –18 mm. long; capsule 2–3 valved, –15 mm. long.

Forest near the coast, Sunday Island.

New Zealand.

Leguminosæ.

Canavalia obtusifolia, D.C.

Ngaio scrub (Coral Bay), Sunday Island. Meyer and Napier Islets.

Norfolk Island, Lord Howe Island, Australia, Tonga, tropics.

Geraniaceæ.

Geranium dissectum, L., var. australe, Benth.

Cliffs, Sunday Island (Cheeseman).

Norfolk Island, New Zealand, Australia, S. America.

Oxalidaceæ.

Oxalis corniculata, L.

Coastal rocks, sand dunes, open places in forest, scrub, buffalo-grass meadow, Sunday Island. Beard-grass meadow, Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Tonga, cosmopolitan.

Rutaceæ.

Melicope ternata, Forst.

Flowers April to October.

Forest, Sunday Island.

New Zealand.

Euphorbiaceæ.

Homolanthus polyandrus (Hook. f.), Cheeseman.

Mr. Cheeseman in 1887 recorded this tree as “not uncommon in sheltered places,” and Mr. R. S. Bell, of Sunday Island, states that less than twenty years ago it was abundant in several localities. At the present time there are a few trees near the settlements and a few others in different parts of the island, all on cliffs inaccessible to goats. These animals absolutely determine the existence of the species. They eat the bark from the trunk as high as they can reach, and the tree dies in consequence. Another enemy of the tree is the larva of a small moth. This grub feeds on the leaves, causing them to die, and frequently young plants entirely stripped of their leaves may be seen.

A few seedlings were seen. Stem erect, terete, bearing prominent scars of fallen leaves, 5 cm. long. Leaves 4 or 5, broadly ovate, obtuse, base not indented, light green with reddish margins. Petioles long, –18 mm.; laminæ 15 x 17 mm., 17 x 20 mm. The petiole joins the leaf-blade about 1 mm. from the lower edge. Leaf-bud small, 4 mm. long.

The tree is usually 8–10 m. tall, with a stout erect stem showing scars of fallen leaves, and moderately dense foliage of delicate leaves which are

– 168 –

light green with reddish margins. Bark roughish, light brown to grey. Branches in whorls of three to five. Twigs green, with prominent scars of fallen leaves.

All parts of the tree exude a white latex when cut or broken. Each young leaf is protected by two imbricate bracts, which fall away when the leaf expands. These bracts may be 47 mm. long. The largest male racemes, some of them 25 cm. long, do not have female flowers at their base, and their lowest pedicels are elongated. The longest raceme noticed bearing female flowers at the base was 15 cm. long. Capsules 15 mm. long, 3- to 4-celled, with a stigma to each cell. One capsule gathered had five cells. This is the only tree on Sunday Island that partially sheds its leaves. From May to July most of the leaves above 10 cm. across fall away.

Flowers September to November. Fruit was gathered in April and May, but probably matures as early as January.

Forest (rare), buffalo-grass meadow, landslip (Denham Bay), Sunday Island.

Endemic. Closely allied to H. pedicellatus, Benth., of Polynesia.

Callitrichaceæ.

Callitriche Muelleri, Sond.

Lakes, Sunday Island.

New Zealand, Australia.

Coriariaceæ.

Coriaria sarmentosa, Forst. f.

C. ruscifolia, Cheeseman (not Linn.), Manual N.Z. Flora, 105.

Flowers and fruits most of the year, but chiefly during the summer months.

Forest, landslip (Denham Bay), pohutukawa forest (crater), tutu scrub (crater), Sunday Island.

New Zealand.

Corynocarpaceæ.

Corynocarpus lævigata, Forst.

Flowers from September, fruit over in March.

Forest, Sunday Island. Ngaio scrub, Meyer Island.

New Zealand.

Violaceæ.

Melicytus ramiflorus, Forst.

Flowers December to May. The tui (Prosthemadera novæ zealandiæ) is very fond of the fruit.

Forest, Sunday Island.

Norfolk Island, New Zealand, Eua (Tonga Group).

Myrtaceæ.

Metrosideros villosa, Sm.

Flowers chiefly in November and December.

Forest, landslip (Denham Bay), pohutukawa forest (crater), tutu scrub (crater), swamp, buffalo-grass meadow, Sunday Island. Scrub, Herald Islets.

Lord Howe Island, New Caledonia, Polynesia.

– 169 –

Halorrhagidaceæ.

Halorrhagis erecta (Murray), Schindler.

Landslip (Denham Bay), buffalo-grass meadow, Sunday Island. Macauley Island (Cheeseman).

New Zealand, Australia.

Araliaceæ.

Nothopanax arboreum (Forst. f.), Seem.

Wet forest, Sunday Island.

New Zealand.

Umbelliferæ.

Hydrocotyle moschata, Forst. f.

Damp banks, open spaces in tutu scrub (crater), Sunday Island.

New Zealand.

Apium prostratum, Lab.

Coastal rocks, sand dunes, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, S. Africa, S. America.

Myrsinaceæ.

Rapanea kermadecensis (Cheeseman), Mez.

Seedling. The exocarp is raised above the ground on the top of the hypocotyle before being cast off. Hypocotyle erect, terete, reddish, 3 cm. high. Cotyledons 2, or sometimes 3, broadly obovate or orbicular, 8–10 mm. long, obscurely serrate, dark green. First leaves broadly obovate, cuneate at the base, obtuse, distal half bluntly serrate, green, petiolate; lamina –15 mm. long. Following few leaves similar, but larger, and serrations more pronounced.

Flowers hermaphrodite, small, greenish with dark spots; calyx 5-lobed; lobes triangular, 1 mm. long, the edges beset with short thick hairs. Corolla divided nearly to the base into 5 lobes; lobes 2 mm. long, revolute, oblong, rounded at the apex, edges fringed with short thick hairs. Anthers sessile on the lobes of the corolla, sagittate, 1 mm. long. Ovary globose; stigma large, sessile, capitate, lobed.

Fruit globose, sunken at the top, dark purple, 1-seeded, 7–8 mm. in diameter.

Flowers from August through the summer, ripe fruit February to June (chiefly). Flowers and ripe fruit may be seen on the same twig.

Forest, Sunday Island. Scrub, Meyer Island.

Endemic. Allied to R. crassifolia (R. Br.), Mez., of Norfolk Island and Australia.

Primulaceæ.

Samolus repens (Forst.), Pers., var. strica, Cockayne.

Coastal rocks, Sunday Island. Dayrell Islet.

Norfolk Island, New Zealand, Australia, New Caledonia (distribution of the species).

– 170 –

Convolvulaceæ.

Ipomæa pes caprae (L.), Roth.

Flowers November to April. Fasciation was noted in one plant on the north coast of Sunday Island. Fourteen stems were joined in one.

Gravel flat, sand dunes, coastal rocks, Sunday Island.

Norfolk Island, Lord Howe Island, Australia, Tonga, tropics.

Ipomæ palmata, Forsk.

Sea-cliffs, buffalo-grass meadow, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, tropics.

Calystegia sepium (L.), R. Br.

Waste places on Sunday Island (Cheeseman).

New Zealand, Australia, cosmopolitan.

Calystegia Soldanella (L.), R. Br.

Coastal rocks, gravel flat, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, cosmopolitan.

Solanaceæ.

Solanum aviculare, Forst. f.

Forest, Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia.

Solanum nigrum, L.

A pubescent and a glabrous variety were noticed, the former on the Herald Islets, the latter in waste places on Sunday and Meyer Islands. Macauley Island (Cheeseman). Mariscus slopes, Curtis Island (pubescent variety).

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, cosmopolitan.

Scrophulariaceæ.

Veronica breviracemosa, n. sp.

V. fruticosa, 1–2 m. alta, ramis ultimis subcompressis, puberulis. Folia sessilia, patual, –115 mm. longa, –27 mm. lata, elliptico-lanceolata v. oblongo-lanceolata, acuta, integra, glabra. Racemi 4–5 cm. longi, denseflori, puberuli, foliis breviores. Calyx 4-partitus, lobis ovato-lanceolatis, acutis, puberulis. Corolla 4-partita, calyce ½ longior; tubo breve calyce ½ breviora; lobis ovatis, acutis. Capsula 6 mm. longa, calyce ½ longior, late ovata, acuta, compressa, glabra.

An irregularly laxly branched shrub, about 1 m. high; branchlets green, 2-angled, puberulous. Leaves sessile, spreading, 115 x 27 mm., 57 x 19 mm., 80 x 20 mm., elliptic-lanceolate to oblong-lanceolate, acute, narrowed at the base, entire, light green, glabrous, minutely puberulous on the midrib and margins near the base. Racemes 4–5 cm. long, shorter than the leaves, flowers crowded; rachis, pedicels, and bracts puberulous. Flowers 5 mm. in diameter, white to pale lilac. Calyx 4-partite, the two inner divisions smaller than the two outer, segments lanceolate to ovate-lanceolate, acute, puberulous. Corolla 1 ½ times the length of the calyx; tube short, about half the length of sepals; limb 4-lobed, lobes ovate, acute, 3 outer opposed to 1 inner. Capsule 1 ½ times the length of the calyx, 6 mm. long, acute, broadly ovate, compressed, glabrous.

– 171 –

Distinguished by the large broad leaves, racemes shorter than the leaves, and very short corolla-tubes.

Mr. Cheeseman includes this species under V. salicifolia in the “Manual of the N.Z. Flora,” with the note that it is perhaps a distinct species.

This plant was formerly fairly plentiful, but has been almost killed out by goats, and is now found only on cliffs and other places inaccessible to those animals.

Inland cliffs, landslip (Denham Bay), Sunday Island.

Endemic. Resembles V. macrocarpa of New Zealand, differing principally in the shorter racemes and corolla-tubes.

Myoporaceæ.

Myoporum lætum, Forst. f.

Ngaio scrub, coastal rocks, forest, gravel flat, Mariscus slopes, landslip (Denham Bay), buffalo-grass meadow, pohutukawa forest (crater), Sunday Island. Ngaio scrub, Herald Islets. Macauley Island (Cheeseman).

New Zealand.

Rubiaceæ.

Coprosma petiolata, Hook. f.

This species occurs in Denham Bay forest as a small tree, 4–6 m. tall, with a leaning stem covered with rough, dark-grey bark. Head rounded foliage moderately dense. Leaf-laminæ of male plant 29 x 18 mm., 32 x 20 mm., 34 x 20 mm.; of female plant usually larger, 45 x 20 mm., 50 x 24 mm., 52 x 25 mm.

Flowers May to September. Ripe fruit January to May.

Fruit usually three in a cluster; reddish; variable in size and form; smaller ones ovoid, 7 x 6 mm., 9 x 7.5 mm.; larger ones compressed, more or less distinctly 2-lobed, 10 x 10 mm.

Coastal rocks and cliffs, inland cliffs (rare), dry forest (Denham Bay, rare), landslip (Denham Bay), Sunday Island. Coastal rocks and cliffs, Herald Islets. Macauley and Curtis Islands (Cheeseman).

Endemic. Closely allied to C. Baueri, Endl., of Norfolk Island, Lord Howe Island, and New Zealand; and to C. chathamica, Cockayne, of the Chatham Islands.

Mr. Cheeseman (1; p. 168) records C. Baueri from the Kermadecs. I did not see it, though I searched in the places indicated. I would suggest that the young large-leaved branches of C. petiolata were mistaken for it, and recommend that until authentic specimens are obtained the name be crossed off the list of plants inhabiting the Kermadec Islands.

Coprosma acutifolia, Hook. f.

Flowers May to September. Ripe fruit January to May.

Forest, landslip (Denham Bay), pohutukawa forest (crater), Sunday Island.

Endemic. Closely allied to C. lævigata, Cheeseman, from Rarotonga; and resembles C. tenuifolia, Cheeseman, from New Zealand.

Cucurbitaceæ.

Sicyos australis, Endl.

Ngaio scrub, forest near the coast, Mariscus slopes, Sunday Island. Scrub, Meyer Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Polynesia, cosmopolitan.

– 172 –

Campanulaceæ.

Lobelia anceps, L. f.

Coastal and inland rocks, Sunday Island. Herald Islets. Cliffs, Macauley Island. Curtis Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia, cosmopolitan.

Wahlenbergia gracilis (Forst. f.), A. D. C.

Beard-grass meadow, Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, New Caledonia, Tonga, E. Asia, S. Africa.

Goodeniaceæ.

Scævola gracilis, Hook. f.

Flowers and fruits profusely throughout the year.

Fruit an indehiscent drupe, axillary, solitary, sessile, ovoid, sometimes almost globose, truncate, sunken at both ends, 10.5 x 9 mm., 10.5 x 8 mm., 10.5 x 10.5 mm. Exocarp succulent, thick, white. Endocarp hard, bony, 2-celled, black, ovoid, mucronate, surface covered with indistinct longitudinal rows of nodules 5.5 x 4 mm. Seed oval, compressed, 3 x 2 x 1 mm., white. Seed-coat fitting close to the endocarp, and usually sticking to it when the seed is extracted. Embryo erect, imbedded in a fleshy endosperm, cotyledons linear.

Gravel flat, coastal cliffs, sand dunes, landslip (Denham Bay), tutu scrub (crater), open rocky places in forest, Sunday Island. Macauley Island (Cheeseman).

Endemic.

Compositæ.

Lagenophora pumila (Forst. f.), Cheeseman.

Inland rocks, Sunday Island.

New Zealand.

Gnaphalium japonicum, Thunb.

Gravel flat, landslip (Denham Bay), Sunday Island. Macauley Island (Cheeseman).

Norfolk Island, Lord Howe Island, New Zealand, Australia, Malaya.

Gnaphalium collinum, Lab.

Inland rocks, Sunday Island. Macauley Island (Cheeseman).

New Zealand, Australia.

Gnaphalium luteo-album, L.

Coastal rocks, landslip (Denham Bay), tutu scrub (crater), Sunday Island. Cliffs, Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, cosmopolitan.

Siegesbeckia orientalis, L.

Cliffs, Sunday Island. Scrub, Meyer Island.

Norfolk Island, New Zealand, Australia, Tonga, warm countries.

Bidens pilosa, L.

Ngaio scrub, Ageratum meadow, and waste places, Sunday Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia, Tonga, warm countries.

– 173 –

Cotula australis, Hook. f.

Inland rocks, Sunday Island. Rocks, Herald Islets. Beard-grass meadow, Macauley Island.

Norfolk Island, Lord Howe Island, New Zealand, Australia.

Senecio lautus, Forst. f.

French Rock.

New Zealand, Australia.

Erechtites prenanthoides (A. Rich.), D.C.

Gravel flat, inland cliffs and rocks, Sunday Island.

New Zealand, Australia.

IX. List of Introduced Plants on Sunday Island.

Gramineæ.

  • Polypogon monspeliensis, Desf.

  • Festuca Myuros, L.

  • F. bromoides, L.

  • Cynodon Dactylon, Pers.

  • Dactylis glomerata, L.

  • Poa annua, L.

  • P. pratensis, L.

  • Lolium perenne, L.

  • Holcus lanatus, L.

  • Paspalum dilatatum, Poir.

  • Sporobolus indicus, R. Br.

  • Briza minor, L.

  • Stenotaphrum glabrum, Trin.

  • Bromus unioloides, H.B.K.

  • Anthoxanthum odoratum, L.

Liliaceæ.
Cordyline terminalis, Kunth.

The Polynesian ti (Cordyline terminalis) occurs in several places on Sunday Island, such as Denham Bay, Terraces, and Coral Bay, all being habitable parts. There is one plant on Meyer Island, and one or two in the forest on Sunday Island. The species does not spread into the forest, but has every appearance of being a survivor of the abandoned cultivations of a native race, of whose occupation on Sunday Island there is good evidence. The Sunday Island plant appears to be a highly cultivated variety; it flowers regularly, but has never been known to bear fruit; it is propagated by means of its roots. I have no hesitation in including it among the list of plants introduced by man.

Polygonaceæ.

  • Rumex obtusifolius, L.

  • R. Acetosella, L.

Caryophyllaceæ.

  • Stellaria media, Vill.

  • Cerastium viscosum, L.

  • Silene anglica, L.

  • Polycarpon tetraphyllum, L.

Cruciferæ.

  • Lepidium ruderale, L.

  • Brassica adpressa, Boiss.

  • Coronopus didymus, Sm.

Fumariaceæ.

Fumaria muralis, Sond.

Leguminosæ.

  • Trifolium repens, L.

  • T. pratense, L.

  • T. procumbens, L.

  • Medicago denticulata, Wild.

– 174 –

Geraniaceæ.

Geranium molle, L.

Euphorbiaceæ.

  • Euphorbia Peplus, L.

  • E. pilulifera, L.

  • Ricinus communis, L.

  • Aleurites moluccana, Willd.

The candle-nut (Aleurites moluccana), like the Polynesian ti, appears to be the survivor of the abandoned cultivations of a native race. It now occurs in two places only on Sunday Island—there is a small clump of trees in Coral Bay and another on Low Flat. The trees in Denham Bay and the Terraces have been planted quite recently. It was formerly in other places, but has died out, leaving only dead fruit scattered about the ground. It is thus scarcely able to hold its ground in the forest.

Malvaceæ.

Sida rhombifolia, L.

Apocynaceæ.

Vinca rosea, L.

Solanaceæ.

  • Physalis peruviana, L.

  • Nicotiana Tabaccum, L.

  • Datura Stramonium, L.

Scrophulariaceæ.

  • Veronica arvensis, L.

  • V. agrestis, L.

Plantaginaceæ.

  • Plantago major, L.

  • P. lanceolata, L.

Compositæ.

  • Ageratum conyzoides, L.

  • Erigeron canadense, L.

  • E. linifolius, Willd.

  • Senecio vulgaris, L.

  • Hypocharis radicata, L.

  • Taraxacum officinale, Weber.

  • Sonchus oleraceus, L.

  • S. asper, Hill.

The following introduced species were observed on Macauley Island—Polypogon monspeliensis, Festuca bromoides, Stellaria media, Erigeron canadense; on Curtis Island—Sonchus oleraceus.

X. Bibliography.

1. Cheeseman, T. F. “On the Flora of the Kermadec Islands.” Trans. N.Z. Inst., vol. xx, p. 151; 1888.

2. — “On some Recent Additions to the New Zealand Flora.” Trans. N.Z. Inst., vol. xxiv, p. 410; 1892.

3. — “The Flora of Rarotonga.” Trans. Linn. Soc. (Bot.), vol. vi, p. 267; 1903.

4. — “Manual of the New Zealand Flora.” Wellington, 1906.

5. Cockayne, L. “Some Observations on the Coastal Vegetation of the South Island of New Zealand.” Trans. N.Z. Inst., vol. xxxix, p. 312; 1907.

6. " “Report of a Botanical Survey of the Tongariro National Park.” Wellington, 1908.

7. Hackel, E. “On New Species of Grasses from New Zealand.” Trans. N.Z. Inst., vol. xxxv, p. 378; 1903.

8. Hedley, C. “A Zoogeographic Scheme for the Mid-Pacific.” Proc. Linn. Soc. N.S.W., vol. xxiv, p. 391; 1899.

– 175 –

9. Hemsley, W. B. “The Flora of Lord Howe Island.” Annals of Botany, vol. x, p. 221; 1896.

10. Hooker, Sir J. D. “On the Botany of Raoul Island, one of the Kermadec Group.” Jour. Linn. Soc. (Bot.), vol. i, p. 125; 1857.

11. " “Handbook of the New Zealand Flora,” vols. i, ii. London, 1864–66.

12. Hutton, F. W. “On the Origin of the Fauna and Flora of New Zealand.” N.Z. Jour. Science, vol. ii, pp. 1, 249; 1884.

13. Maiden, J. H. “Observations on the Vegetation of Lord Howe Island.” Proc. Linn. Soc. N.S.W., vol. xxiii, p. 112; 1898.

14. " “The Flora of Norfolk Island.” Proc. Linn. Soc. N.S.W., vol. xxviii, p. 692; 1904.

15. Parker, T. J., and Haswell, W. A. “Text-book of Zoology,” vol. ii; 1897.

16. Schimper, A. F. W. “Plant-geography upon a Physiological Basis” (English translation). Oxford, 1903.

17. Smith, S. P. “The Kermadec Islands: their Capabilities and Extent.” Wellington, 1887.

18. Tate, R. “On the Geographic Relations of the Floras of Norfolk and Lord Howe Islands.” Macleay Memorial Volume. Sydney, 1893.

19. Wallace, A. R. “The Geographical Distribution of Animals,” vol. i. London, 1876.

Explanation of Plates XII to XXIII.
Plate XII.

Path of a hurricane through forest in Denham Bay, Sunday Island. The fallen trees are Metrosideros villosa. In centre, young shrubs of Myoporum lætum.

Plate XIII.

Ngaio scrub, Terraces, Sunday Island, showing ngaio (Myoporum lætum) killed by burrowing shearwaters (Puffinus chlororhynchus). The undergrowth is Macropiper excelsum major.

Plate XIV.

Gravel-flat vegetation, Denham Bay, Sunday Island. Ipomæa pes capræ in flower. Beyond, Scirpus nodosus.

Plate XV.

Vegetation on inland rocks, Terraces, Sunday Island. The ferns are Asplenium Shuttleworthianum. On right—below, Lobelia anceps; above, Cyclophorus serpens.

Plate XVI.

Interior of dry forest, Denham Bay, Sunday Island. On left, Cyathea Milnei; on right, Rapanea kermadecensis.

Plate XVII.

Interior of palm (Rhopalostylis Baueri) forest, Big Hill, Sunday Island.

Plate XVIII.

Interior of wet forest on Mount Junction, Sunday Island. Trunks of Cyathea kermadecensis covered with Hymenophyllum demissum, and other ferns.

Plate XIX.

Landslip, Denham Bay, Sunday Island, showing rounded shrubs of Myoporum lætum and Coriaria sarmentosa.

Plate XX.

Interior of pohutukawa (Metrosideros) forest, crater, Sunday Island. (Photo, W. L. Wallace.)

Plate XXI.

Cyathea Milnei, Sunday Island.

Plate XXII.

Cyathea kermadecensis, Sunday Island.

Plate XXIII.

Flowering branch of Rapanea kermadecensis, Sunday Island, showing rolled leaves.