Art. XLV.—On the New Zealand Species of Pittosporum, with Descriptions of New Species.
[Read before the Auckland Institute, 2nd October, 1871.]
Amongst the genera of New Zealand plants which occupy a prominent position in the Flora, alike from their wide range of distribution, relative abundance, and number of species, the genus Pittosporum takes an important place. Although rarely of social character, its members form a considerable portion of the woodland Flora, and from their great variety in habit, stature, and inflorescence, present special features of interest.
In the “Flora Novæ Zelandiæ” ten species are described; in the “Handbook of the New Zealand Flora” the number is increased to thirteen, one of the additional forms having been described as a variety in the first-named work. Since the publication of the “Handbook” the number of species or sub-species has been increased by more than one-half, and the doubts expressed by
its author as to the specific validity of some of the forms originally described have been confirmed. It is, therefore, of some importance that our present knowledge of the genus should be arranged in a connected form, and made available for further research.
It must, however, be pointed out that the present information is not sufficiently complete to admit of the preparation of a permanent revision of the genus, chiefly owing to the absence of any knowledge of the limits of variation in the southern forms.
The New Zealand species vary from small shrubs one foot in height, to trees of forty feet and upwards; they usually occur on the margins of forests, or in low-growing bush, particularly affecting the sloping sides and spurs of open gullies. P. crassifolium and P. umbellatum are invariably confined to littoral habitats, although often found at a considerable height on the cliffs, P. cornifolium usually, and P. Kirkii occasionally are epiphytic. P. pimeleoides, a remarkably local species, is restricted to clay hills near the Bay of Islands, and from the undiscriminating manner in which the open country has been cleared by fire has become very rare in its limited area. The seeds of all the species are imbedded in a viscid pulp, and a resin is exuded from the bark of P. crassifolium, P. eugenioides, and others.
The genus exhibits a pre-eminently northern distribution in the colony, although a few species have a remarkably restricted range; only two species are known to occur from the North Cape to Invercargill; three species are common to both islands; two are peculiar to the South Island; eleven are confined to the North Island. Of these last eight are not known to occur south of the province of Auckland, and of these, again, four are restricted to the district north of the Auckland Isthmus.
The altitudinal range of the New Zealand species is, with one or two exceptions, extremely limited, as might fairly be expected from its horizontal distribution. P. rigidum and P. Kirkii are known to occur up to 2,000 feet, and will probably be found at greater altitudes in the central ranges of the North Island. P. patulum, a remarkably local species, occurs at 5,000 feet in the province of Nelson.
The absence of any member of the genus from the Auckland Islands and the Chathams is significant, although there is reason to believe that at least one of the forms of P. tenuifolium is found in the latter group. On the other hand, the islands of the east coast of the province of Auckland exhibit a profusion of species—seven are found on the small island of Kawau, and nine on the Great Barrier.
The trunk of P. eugenioides attains a diameter of nearly two feet, and is occasionally rivalled by P. crassifolium, which is usually much smaller. The wood is perishable and of little use, even for firewood; from its whiteness and
density it might prove of value to the inlayer and wood-turner. The only economic purposes to which any part of the plant has been adapted, so far as I am aware, is the use of the gummy matter, in which the seeds are imbedded, to mix with the juice of the sow-thistle as a masticatory by the natives, who are also said to have mixed the bruised leaves of P. eugenioides with fat, for the sake of the perfume.
P. tenuifolium is the “turpentine tree” of the Otago settlers, who plant it for hedges, as it bears clipping freely.
P. Buchanani and P. eugenioides appear to be constantly diæcious. Other species exhibit a strong tendency in this direction, as well as towards a whorled arrangement of branches and leaves; this is constant in P. cornifolium, frequent in P. reflexum and P. Kirkii, and less developed in P. umbellatum, P. eugenioides, and P. virgatum.
A few species exhibit considerable variation in foliage. P. rigidum and P. patulum, in certain states, can with difficulty be distinguished from such widely different plants as Melicytus micranthus, Melicope simplex, Panax anomalum, and Elæocarpus Hookerianus.
The following arrangement is proposed for the New Zealand species:-
A. Flowers axillary (rarely terminal in P. fasciculatum and P. rigidum).
P. tenuifolium sub-speciesColensoi "fasciculatum
pimeleoides sub-species reflexum
ellipticum sub-species ovatum
P. tenuifolium, Banks and Sol.—Sub-species Colensoi.—Sub-species fasciculatum.
Throughout the islands, not confined to the east coast; the sub-species rare and local.
Flowers in October.
These forms vary considerably in all their parts, so that it would not be difficult to obtain a connected series of specimens, which should include the whole. I fully agree with Dr. Hooker in considering them much too closely allied to admit of their taking specific rank, although, perhaps, the differences are too highly developed to allow of their being treated as mere varieties. P. Colensoi is said by Buchanan to be frequent in the north. I never met with it north
of the Auckland Isthmus, and consider it a form of comparatively rare occurrence. Small forms of the typical P. tenuifolium are often referred to P. Colensoi by collectors.
2. P. Buchanani, Hook. f. North Island, Mongonui, J. Buchanan; near Mount Egmont. Dr. Hector informed me this species had not been found at Tongariro, as stated in the “Handbook.”
3. P. Huttonianum, Kirk, Trans. N.Z. Inst., Vol. II., p. 92. Varying in habit and station from a laxly-branched shrub to a small tree 12–25 feet in height with strict branches; bark black, or dark brown; branches slender, and with the young leaves and petioles clothed with white floccose tomentum; leaves alternate, oblong or ovate, obtuse or acute, 3–5 inches long, slightly coriaceous; petioles slender, ½–¾ inch long. Flowers axillary, solitary, or rarely in twos on a common pedicel; peduncles downy, ½–¾ inch long; sepals lanceolate, acute, bullate at the base, downy; petals ligulate, sharply recurved at about two-thirds their length, the corolla never presenting the rotate appearance of P. tenuifolium; anthers very long, ovary pubescent, bracts at the base of the peduncle deciduous; capsules erect, pyriform, downy, 2–3-valved, larger than in P. tenuifolium.
North Island, Whangarei, J. Buchanan; Great Barrier Island, Thames Goldfield.
4. P. rigidum, Hook. f. The flowers are both axillary and terminal.
North and South Islands; in mountain districts rare.
I have received small flowerless branches of sinuate-dentate leaves, collected by Major Mair in the Uriwera country, which may be identical with this plant, and I have collected similar forms on the Cape Colville ranges and in the Kaipara district.
5. P. obcordatum, Raoul. South Island, Banks Peninsula.
I am informed by Mr. Potts that the capsule is small, globose, 2-valved.
6. P. pimeleoides, R. Cunn. A weak, much-branched shrub, 1–8 feet high; young shoots and leaves silky pubescent, linear-oblong, scattered or whorled, patent or appressed, acute or obtuse, entire. Flowers terminal in clusters of 3–6; peduncles 1-flowered, slender, silky, ¼–1 inch long; petals subulate, recurved, yellow, with a purple stripe; capsules erect, ovate-acuminate or conical, downy, 2-valved; valves membranous at length, deciduous, the nuts retaining their position on the peduncle long after the valves have fallen.
Sub-species pimeleoides, proper. Much and repeatedly branched, the branches and leaves usually whorled, 1–1¼ inches long, ¼ inch wide, flowers clustered, valves of capsule with tips recurved.
Sub-species reflexum, R. Cunn. Leaves scattered, rarely whorled,
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
linear, lanceolate acuminate, 1/16 inch wide, crowded. Flowers terminal, solitary or clustered; capsule ovoid-acuminate; tips of valves recurved. Var. Gilliesianum—very slender, leaves crowded, linear-lanceolate, acute, capsule conical, tips of valves straight. P. Gilliesianum, Kirk, Trans. N.Z. Inst., Vol. I., p. 143.
North Island, rare, Mongonui, Bay of Islands, and Whangaroa.
Flowers in April.
In size and habit there is a wide difference between the sub-species, but the fruit is closely alike in both. I have seen no specimens of P. reflexum with axillary flowers.
7.P. cornifolium, A. Cunn. Usually epiphytic, rarely terrestrial; branches often scarred with the marks of fallen leaves.
North Island, Spirits Bay to Cook Straits.
Flowers from August to November.
8. P. Kirkii, Hook. f., Trans. N.Z. Inst., Vol. II., p. 92. A laxly branched shrub, 3 to 15 feet high; branchlets stout, ascending; bark reddish purple; leaves erect, alternate, crowded or whorled, glabrous, linear-obovate, acute or obtuse, 2–5 inches long, narrowed into rather broad purple petioles, excessively coriaceous, pale green above, lighter below, midrib stout, prominent and curiously flattened beneath. Flowers terminal in 3–7 flowered umbels; peduncles slightly decurved; sepals broadly lanceolate, with membranous margin; petals ligulate, recurved, bright yellow; filaments short; ovary with a few long hairs, and narrowed into the short style; stigma 2-lobed; capsules erect, clustered, glabrous, elliptic, 1½ inches long, obtuse, 2–3-valved, remarkably compressed.
North Island; rocky woods, Whangarei, J. Buchanan; Great Barrier Island and Omaha, T.K.; Titirangi, T. F. Cheeseman; Cape Colville and Thames, T.K. Altitudinal range 1,000 to 2,300 feet.
Flowers in December. Often epiphytic.
9. P. umbellatum, Banks and Sol. Var. cordatum. Leaves linear spathulate, narrowed into the petioles, capsules cordate, valves not lobed.
North Island; always near the sea, from the North Cape to Poverty Bay. Var. cordatum, Great Barrier Island.
Flowers in October.
Comparatively rare on the west coast. This species and P. crassifolium have the same range, and evince the same preference for a littoral habitat. Probably both will be found to extend to the East Cape or still further south.
10. P. virgatum, n. s. A slender twiggy tree, 20–25 feet high; young shoots, leaves, and pedicels clothed with pale ferruginous pubescence; leaves linear-lanceolate or ovate, or obovate, entire or variously lobed and
toothed. Flowers terminal, in 2–3-flowered umbels, or solitary; pedicels short, decurved; flowers small; sepals linear, silky; petals recurved at the tips; ovary conical, hirsute; stigma 2-lobed; capsules erect, globose, woody, 2-valved; valves 2-lobed, granulated on both surfaces.
Var. cratœgifolia—leaves linear-lanceolate, irregularly lobed and toothed.
Var. serratum—leaves ovate, acute, crenate-serrate or dentate. In the young state of all the varieties the leaves are deeply incised and lobed.
North Island, Whangaroa North, Great Barrier Island.
Flowers in October.
11. P. patulum, Hook. f. Branches stout, glabrous; young leaves narrow linear, lobed or pinnatifid, 2 inches long; mature leaves spreading 1–1½ inches long, ⅓ broad, linear-oblong, narrowed at the base into a short broad petiole, obtuse, entire or crenate-serrate, very coriaceous and shining. Flowers in terminal 4–6-flowered umbels; pedicels patent, 1″ long, with scattered pubescence; sepals and petals not seen; ovary glabrous; style elongated; capsule nearly globose, compressed, broader than long; valves somewhat woody, brown, 2-lobed.
South Island, Wairau Mountains, altitude 5,000 feet, “Handbook New Zealand Flora.”
The description in the “Handbook” is avowedly drawn from “a single fruiting specimen,” and the fruit is said to be axillary. The valuable specimens for which I am indebted to Mr. W. T. L. Travers show both flower and fruit strictly terminal; by the time the fruit has arrived at maturity the peduncle has contracted to half its original length, and has become rigid and erect. The latter characteristic is manifested in P. Kirkii and P. virgatum, etc.
12 P. Ralphii, Kirk, Trans. N.Z. Inst., Vol. III., p. 161. A laxly branched shrub, 8 to 12 feet high in cultivation, with dark brown bark; branches spreading, young branches tomentose; leaves oblong or obovate, on long slender petioles, acute or obtuse, 3″–5″ long, 1″–2″ wide, coriaceous, clothed beneath with buff tomentum. Flowers in terminal 3–8-flowered umbels; peduncles ½”–⅝” long, tomentose, decurved in fruit; sepals linear, obtuse, tomentose; petals narrow, recurved; capsules rounded, 3-lobed and valved.
North Island, Patea, Dr. Ralph; cultivated at Wellington, J. Buchanan; Great Barrier Island, W. J. Palmer.
Easily distinguished from P. crassifolium and P. umbellatum by its slender spreading branches and oblong leaves; from P. crassifolium it differs in addition in the larger leaves, which are never narrowed into the petiole or have the margins recurved, and are less coriaceous and tomentose,
and in the capsules being less than one-half the size of that species. From P. umbellatum it further differs in the tomentose leaves, woody 3-valved capsules, and large seeds.
13. P. crassifolium, Banks and Sol. An erect shrub or tree, 10 to 30 feet high, with black bark, branches stout, young shoots, leaves, and peduncles clothed with white tomentum; leaves alternate, narrow-obovate or linear-obovate, narrowed into the stout peduncle, acute or obtuse, excessively coriaceous, densely tomentose below, margins recurved. Flowers terminal, solitary or in 2–4-flowered umbels; bracts ovate, ciliate; pedicels decurved; sepals linear-oblong, tomentose; petals recurved, large; capsules terminal, ¾”–1.¼” in diameter, 3-valved and lobed, on stout decurved pedicels 1″ long or more, usually solitary when mature; valves excessively stout and woody, downy.
Var. strictum—umbels terminal; capsules 3–5; pedicels strict.
North Island, by the sea, Spirits Bay to Poverty Bay.
Flowers in September.
As some confusion appears to exist amongst collectors respecting this very distinct species, I have ventured to add a few characters omitted from its diagnosis in the “Handbook.”
14. P. intermedium, n. s. A small tree with black bark, in habit and foliage resembling large specimens of P. tenuifolium; young leaves and shoots pubescent; leaves 1½”–2″ long, obovate, acuminate, narrowed at the base, flat, midrib pubescent, slightly coriaceous, erect. Flowers not seen; capsules terminal, on stout curved pedicels, solitary or in 2–3-flowered umbels, ovate-acuminate, ¾” in diameter, 3-valved, downy.
North Island, Kawau Island.
I give this well-marked form specific rank with some hesitation; in foliage it resembles large forms of P. tenuifolium, while the capsule partakes of the characters of P. crassifolium and P. ellipticum. Dr. Hooker and Mr. Colenso consider it a new species, still it is possible that further observation may show the wisdom of uniting it with one or other of the above. I have been tempted to attribute its peculiarities to hybridization.
15. P. ellipticum, n. s. A small tree, with black bark; branches erect or spreading, puberulous; leaves ovate-lanceolate, or elliptic, or obovate, obtuse or acute, coriaceous, partially clothed with ferruginous pubescence beneath. Flowers in terminal 2–5-flowered umbels; pedicels short, decurved, tomentose; capsules globose, flattened, 2-valved, downy, stout.
Sub-species ellipticum, proper. Leaves ovate-lanceolate or elliptic; in the young state densely clothed on both surfaces with rusty coloured pubescence. Flowers terminal, in 3–5-flowered umbels; sepals broad,
ovate, pubescent; petals recurved, reddish brown or chocolate coloured; ovary hirsute; style slender; stigma 2-lobed; capsules ovate, acuminate at both ends, with slightly flattened sides; valves faintly 2-lobed.
Sub-species ovatum. Leaves obovate or ovate-acuminate, spreading, 1½”–2″ long, pubescent beneath. Flowers not seen; capsules 2–4, in terminal clusters; peduncles stout, ½”–¾” long, globose, downy, 2-valved.
North Island. P. ellipticum—Manaia Hills; ovatum—Whangaroa North, Manaia Hills, T.K.; western part of the Titirangi district, T.K.
Flowers in October.
The dense ferruginous pubescence covering the young twigs, leaves, and inflorescence, give this species a singular appearance in the spring months.
16. P. eugenioides, A. Cunn. In forests throughout the islands.
Flowers in August.
I am informed by Dr. Hooker that several of the New Zealand species produce self-sown hybrid forms freely under cultivation in the south of France.