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Volume 49, 1916
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Art. X.—Notes of a Botanical Excursion to Long Island, near Stewart Island, including a List of Species.

[Read before the Otago Institute, 1st August, 1916, received by Editors, 30th December, 1916, issued separately, 9th July, 1917.]

General.

Long Island lies off the south-west of Stewart Island, in latitude 47° 15′ South and longitude 168° 27′ East. It is the largest of a group of small islands in this locality, and is about three miles long by about one mile wide. It is situate a mile and half from the mainland of Stewart Island at its nearest point. This island forms one of the most southerly outliers of the Stewart Island group; it is composed of granitic rock covered with peat. It stands about 800 ft. high, and is fairly steep on the sides, but has an undulating surface. Almost the whole of its steep sides are clothed with scrub and forest, but the top is covered in parts with heath. Some particulars of the various formations will be given later. The island is also known as “Jura,” and by the Stewart Island fishermen as “Big South Cape Island.” This isolated patch, being practically the nearest land to the Snares, situated sixty miles to the south of it, is scientifically of exceptional interest, so I make no apology for placing upon record some notes as to its plant-covering. During the Easter holidays this year—namely, on the 21st April, 1916—I spent about nine hours on the island noting its vegetation. I was accompanied by Mr. W. A. Thomson, of Dunedin, who is an ardent and experienced plant-collector, and he materially assisted me in my investigations. Owing to the size of the island and the rough nature of its covering, it is obvious that no very exhaustive examination could be made of the flora, and therefore a number of species may have been overlooked. This is the more likely when one considers the late period of the season when our visit was made, and the fact that many plants, such as the Orchidaceae, are then easily passed by.

Ecological Conditions.

Perhaps nowhere in the world can stormier conditions be found than those of these outlying islands off the south coast of Stewart Island. The strong prevailing south-west winds and seas strike these islands with full force. The bare rocks and the wind-shorn plants on the weather side show the effect of this. On the north side, however, there is more shelter, and consequently a less wind-swept vegetation. Heavy rains drench the peaty soil for a great number of days in each year. In common with the rest of Stewart Island there is, I believe, a mild winter climate, and, although at the time of our visit there was a very hot sun and still atmosphere, the average summer temperature is probably low. The soil, as before mentioned, is of a peaty nature, and is much enriched by the droppings of the petrels (Puffinus griseus), whose burrows are very plentiful on the steep scrubby sides of the island. These tunnels must also assist materially in draining and aerating the soil.

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Plant Formations.

These can best be described under the headings (1) scrub, (2) rocks and cliffs, (3) heath.

1. Scrub.

I have chosen the term “scrub” as it best describes the vegetation of the steep sides of the island. Throughout this formation in the more sheltered parts will be found patches which might be called “forest,” but as the majority of the plants are of the Olearia type, or much stunted, the formation as a whole is best designated “scrub.” On approaching the island the general physiognomy is grey-green with yellowish-brown patches, and, higher up, blotches of a darker colour. The grey-green patches are of that peculiar globose appearance so characteristic of the Olearia scrub formation of the Stewart Island coast. On a close examination it is at once seen that the scrub consists of Olearia angustifolia next the sea, with O. Colensoi abundant and Senecio rotundifolius behind the first fringe, while the yellowish-brown colour is produced by Dracophyllum longifolium, which is fairly plentiful. The darker patches, which usually occupy the sheltered depressions, consist of Metrosideros lucida. The whole surface of this formation is smooth and rounded, showing the effect of the strong winds which sweep these islands. Here and there a green patch of Veronica elliptica is visible, especially near the sea. This is more marked where there has been some clearing round the mutton-birders' huts. In open places considerable patches of Poa foliosa are found, with an occasional tuft of Carex trifida or Microlaena avenacea. Under the scrub the ground-floor is covered by patches of Stilbocarpa Lyallii, Asplenium flaccidum, A. scleroprium, A. lucidum, A. obtusatum, and Polystichum vestitum, while Polypodium diversifolium climbs over the fallen trees. Among smaller plants I noted Stellaria parviflora and Nertera depressa. At a higher elevation the following species were added to the formation: Nothopanax Colensoi, N. Edgerleyi, Metrosideros lucida, Coprosma foetidissima, C. Colensoi, Astelia nervosa, and the ferns Histiopteris incisa, Dicksonia squariosa, and Hemitelia Smithii.

2. Rocks and Cliffs

A typical cliff association was noted in a situation where the full force of the wind strikes. The rocks were absolutely bare for a height of between 50 ft. and 60 ft, when a grey-green fringe of Poa Astoni altered the physiognomy of the granitic rock wall. On the cliffs Crassula moschata was common, while Myosotis albida, Tetragonia trigyna, Mesembryanthemum australe, and Apium prostratum were sparingly found. This was succeeded by Olearia angustifolia, under which the shore-fern Blechnum durum was growing in considerable patches. Here and there were tussocks of Scirpus nodosus. This association also contained some Scirpus aucklandicus and Anisotome intermedia var., but gradually merged into the scrub formation above described.

3. Heath

On a peaty saddle crossing over the top of the island and forming a wind-funnel there was a most marked heath formation, consisting of Phormium Cookianum, Leptospermum scoparium, Dracophyllum longifolium (the two latter fairly abundant), Olearia arborescens, Styphelia acerosa, S. empetrifolia, Hymenophyllum rufescens, Veronica buxifolia, Gaultheria erecta, Pentachondra pumila, Lycopodium varium (in large clumps), Coprosma

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Colensoi, Enargia parviflora, with stunted Olearia Colensoi, Metrosideros lucida, and Senecio rotundifolius, and the bog-plants Celmisia longifolia var., Astelia linearis, Oreobolus pectinatus, O. strictus; also Gahnia procera and Carex trifida. The ground was also dotted over with coral moss, and in parts with Lycopodium ramulosum. The whole of this formation was very wind-swept. The Leptospermum was lying prostrate, and formed a close mat over considerable patches, the plants being rooted right along to the ends of the branches; the ultimate tips were erect and close together, forming a solid mat. Adjoining the above heath there was a low-scrub association consisting of many of the heath-plants above mentioned, but also containing Dacrydium intermedium fairly plentifully with Weinmannia racemosa, Coprosma Colensoi, and Griselinia littoralis. In the wetter parts of the heath I also noted Donatia novae-zelandiae, Hydrocotyle novae-zelandiae, Drosera spathulata, Gleichenia circinata, and Schizaea fistulosa var australis; and, where the ground was drier, Senecio bellidioides var., Cardamine heterophylla, Phormium tenax (rare), and the ferns Pteridium esculentum and Blechnum capense.

Summary.

From the list appended hereto it will be seen that the number of species noted was seventy-five, spread over fifty-three genera and twenty-nine families. I do not think that further investigation will disclose many new species on these outlying islands, the ecological conditions being so much alike. From what I saw of the vegetation of several of the islands near Long Island it does not differ materially from that described above. Most of the other islands are, however, much lower in altitude and smaller in area, and have little or no heath formation.

The most interesting feature of the plant-covering of these islands is the epharmonic relations of its members to climatic and edaphic conditions. The wonderful way in which many of the plants adapt themselves to their environment is most instructive.

If we compare the published list of species from the Solanders, Long Island, and the Breakseas, all of which islands possess much in common in their conditions, it will be seen that they have a considerable percentage of plants in common. Thus out of nineteen species reported from the Solanders*seventeen are found at Long Island, and the other two species, Thelymitra uniflora and Senecio Stewartiae, will most likely upon further investigation also be found. I think also that further examination of the Solanders will disclose many more species there in common with the island now under review, especially in the heath formations, not yet examined, of the higher parts of the island. Of sixty-nine species reported from Breaksea Islands† forty-three are also included in the list appended hereto. This connection is, if anything, more accentuated when the genera are considered.

So many islands scattered over the ocean at such long distances apart and still having so many genera and species in common certainly suggest land connection at some time. The flora common to all extended areas of that time would, by a process of gradual elimination brought about by the altered ecological conditions of a reduced and lowered land surface, suffi-

[Footnote] *L. Cockayne, On a Collection of Plants from the Solanders, Trans. N.Z. Inst., vol. 41, 1909, p. 404.

[Footnote] † D. L. Poppelwell, Notes on the Plant-covering of the Breaksea Islands, Trans. N.Z. Inst., vol. 48, 1916, p. 246.

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ciently account for such slight differences as are now noticeable in the florulas of the various islands. If we compare the florulas of these islands and the Snares we find about seven species common to both the Snares and Long Island. From the list of these—namely, Crassula moschata, Apium prostratum, Myosotis albida, Veronica elliptica, Hierochloe redolens, Poa foliosa, and Asplenium obtusatum—it will be seen that most of them are fairly widely distributed over the southern islands. The characteristic species of the Snares—viz., Stilbocarpa robusta, Anisotome acutifolia, Poa litorosa, and Colobanthus muscoides—have not yet been reported from the Stewart Island group, although some closely allied species are found among the latter. One species, Senecio Stewartiae, is found only on the Snares, Solanders, and Herekopere Islands. At present, therefore, it appears that the Snares do not belong to the Stewart Botanical District, but rather to the Sub-antarctic Province. On the question of plant-distribution on these islands L. Cockayne* and T. F. Cheeseman† have thrown much light in their different papers dealing with the matter.

List of Species
Pteridophyta
.

Hymenophyllaceae.

  • Hymenophyllum rufescens T. Kirk.

Cyatheaceae.

  • Dicksonia squarrosa (Forst. f.) Sw.

  • Hemitelia Smithii (Hook. f.) Hook.

Polypodiaceae.

  • Polystichum vestitum (Forst. f.) Presl.

  • Asplenium obtusatum Forst. f.

  • scleroprium Homb. & Jacq.

  • lucidum Forst. f.

  • flaccidum Forst. f.

  • bulbiferum Forst. f.

  • Blechnum durum (Moore) C. Chr.

  • capense (L.) Schlecht.

  • Histiopteris incisa (Thunb.) J. Sm.

  • Pteridium esculentum (Forst. f.) Cockayne.

  • Polypodium diversifolium Willd.

Gleicheniaceae.

  • Gleichenia circinata Sm.

Schizaeaceae.

  • Schizaea fistulosa Labill. var. australis (Gaud.) Hook. f.

Lycopodiaceae.

  • Lycopodium varium R. Br.

  • ramulosum T. Kirk.

Spermophyta.

Taxaceae.

  • Podocarpus ferrugineus Don.

  • Dacrydium intermedium T. Kirk.

Gramineae.

  • Hierochloe redolens (Forst. f.) R. Br.

  • Microlaena avenacea (Raoul) Hook. f.

  • Poa foliosa Hook. f.

  • Astoni Petrie.

Cyperaceae.

  • Scripus aucklandicus (Hook. f.) Boeck.

  • nodosus (R. Br.) Rottb.

  • Gahnia procera Forst.

  • Oreobolus pectinatus Hook. f.

  • strictus Berggr.

  • Carex lucida Boott.

  • trifida Cav.

[Footnote] * L. Cockayne, A Botanical Excursion during Midwinter to the Southern Islands of New Zealand, Trans. N.Z. Inst., vol 36, 1904, p. 225. See also L. Cockayne, The Ecological Botany of the Subantarctic Islands of New Zealand, Subant. Islands of N. Z., Canterbury Phil. Inst., vol 1, 1909, pp. 182–235.

[Footnote] † T. F. Cheeseman, On the Systematic Botany of the Islands to the South of New Zealand, Subant. Islands of N.Z., Canterbury Phil. Inst., vol. 2, 1909, pp. 389–471.

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Juncaceae.

  • Luzula campestris DC. var.

Liliaceae.

  • Phormium tenax Forst.

  • Cookianum Le Jolis.

  • Enargia parviflora (Banks & Sol.) Hook. f.

  • Astelia linearis Hook. f.

  • nervosa Banks & Sol.

Urticaceae.

  • Urtica australis Hook. f.

Aizoaceae.

  • Mesembryanthemum australe Sol.

  • Tetragonia trigyna Banks & Sol.

Cruciferae.

  • Cardamine heterophylla (Forst. f.) O. E. Schulz.

Droseraceae.

  • Drosera spathulata Labill.

Crassulaceae.

  • Crassula moschata Forst. f.

Cunoniaceae.

  • Weinmannia racemosa L. f.

Myrtaceae.

  • Leptospermum scoparium Forst.

  • Metrosideros lucida (Forst. f.) A. Rich.

Araliaceae.

  • Stilbocarpa Lyallii J. B. Armst.

  • Nothopanax Edgerleyi (Hook. f.) Seem.

  • — —var. serrata T. Kirk.

  • Colensoi (Hook. f.) Seem.

Umbelliferae.

  • Hydrocotyle novae-zelandiae DC.

  • Apium prostratum Labill.

  • Anisotome intermedia Hook. f. var. oblongifolia Kirk?

Cornaceae.

  • Griselinia littoralis Raoul.

Ericaceae.

  • Gaultheria antipoda Forst. f. var. erecta Cheesm.

Epacridaceae.

  • Pentachondra pumila (Forst. f.) R. Br.

  • Styphelia acerosa Sol. var.

  • empetrifolia (Hook. f.) Diels.

  • Dracophyllum longifolium (Forst. f.) R. Br.

Myrsinaceae.

  • Suttonia chathamica (F. Muell.) Mez.

Boraginaceae.

  • Myosotis albida (T. Kirk) Cheesm.

Scrophulariaceae.

  • Veronica elliptica Forst. f.

  • buxifolia Benth. var.

Rubiaceae.

  • Coprosma lucida Forst. f.

  • foetidissima Forst.

  • Colensoi Hook. f.

  • Nertera depressa Banks & Sol.

Stylidiaceae.

  • Donatia novae-zelandiae Hook. f.

Compositae.

  • Olearia angustifolia Hook. f.

  • Colensoi Hook. f.

  • — —var. with large leaves, possibly O. Lyallii Hook. f.

  • arborescens (Forst. f.) Cockayne and Laing.

  • Celmisia longifolia Cass. var.

  • Senecio bellidioides Hook. f. var.

  • rotundifolius Hook. f.