Art. III.—Notes on Pittosporum Dallii.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 46, 1913, Page 19

Art. III.—Notes on Pittosporum Dallii. By T. F. Cheeseman, F.L.S., F.Z.S., Curator of the Auckland Museum. [Read before the Auckland Institute, 3rd December, 1913.] Pittosporum Dallii, which is one of the most distinct species of the genus, was discovered by the late Mr. J. Dall in 1905 in the rugged mountainous country at the back of Collingwood, north-west Nelson. Unfortunately, imperfect fruiting specimens were alone obtained, and although I published the plant in the Appendix to the “Manual of the New Zealand Flora” (p. 1134) the description was in many respects incomplete. It was Mr. Dall's intention to revisit the locality in search of flowers; but an unfortunate accident, from the effects of which he never completely recovered, made it impossible for him to undertake the laborious journey which would have been necessary, and he died in 1912 without obtaining any additional material. Previous to his death, however, he had furnished particulars of the locality to my friend Mr. F. G. Gibbs, so well known from his researches into the botany of the Nelson Provincial District. During the past summer Mr. Gibbs was fortunate enough to find the plant, and to bring away a good series of flowering specimens, together with other information respecting it. From this material I have been able to draw up a much more complete description, and to give some other information respecting the species. Pittosporum Dallii Cheesem., Man. N.Z. Fl. App. 1134. A small round-topped tree from 12 ft. to 18 ft. high; trunk sometimes 8 in. diam.; bark of stem and larger branches light grey. Branchlets stout,

often subwhorled, glabrous; bark reddish. Leaves towards the tips of the branchlets, the lower alternate, the upper subopposite or whorled, 2–4 in. long, 1\2–1 1\2 in. broad, narrow elliptic-oblong or elliptic-lanceolate, acute or somewhat acuminate, rigidly coriaceous, quite glabrous or the very young ones sparingly tomentose, sharply and coarsely serrate; midrib stout, prominent above; veins finely reticulated; petioles stout, reddish, 1\2–3\4 in. long. Flowers numerous, white, fragrant, arranged in a dense terminal compound cyme 1–2 in. diam.; bracts many, deciduous, but conspicuous in the early flowering stage; the lower large, membranous, brownish, oblong or oblong-lanceolate, often 1 in. long; the upper gradually becoming smaller and narrower; the uppermost narrow subulate-lanceolate, 1\3–1\2 in. long; both bracts and pedicels more or less silky-tomentose. Flowers 1\4–2\3 in. long, 1\2 in. diam. when fully expanded; sepals 1\2–2\3 the length of the corolla, narrow linear-subulate, attenuate at the tips; petals linear-obovate or linear-oblong, obtuse, conspicuously veined. Stamens included; anthers rather large, bright yellow. Ovary shortly stipitate, with very numerous ovules to each placenta; style stout, cylindrical. Capsules forming dense clusters at the tips of the branchlets, 1\2 in. long, elliptic-oblong, apiculate, glabrous, 2-valved; valves woody. Seeds numerous, immersed in a viscid gluten; often persistent after the fall of the valves as a viscid ball at the top of the pedicel. Hab.—South Island: Nelson—Mountains behind Collingwood, at Specimen Creek and Snow's Valley, near Boulder Lake; altitude, 3,500 ft. Flowers in January. P. Dallii is not closely related to any other species, either in New Zealand or elsewhere. It is the only New Zealand species with regularly serrate leaves; it is the only species we have with white flowers; and, with the single exception of P. eugenioides, no other of our species has such a well-developed inflorescence. When in flower it must be a very beautiful plant; in fact, Mr. Gibbs goes so far as to say that “it is far more handsome than any of the other Pittosporums that I have seen.” The fragrance of the flowers is another attractive characteristic, although, as Mr. Gibbs remarks, it does not equal P. patulum in that respect. P. Dallii appears to be rare in its only known habitat. Mr. Gibbs informs me that he saw only three or four fully adult trees, which were growing in the open on a grass-covered hillside above Specimen Creek, at an altitude of about 3,500 ft., but he has reason to believe that there were several others higher up the hill. A number of young trees were seen, however, in a small patch of bush not far distant, and others were noticed in the bush on the eastern side of Snow's Valley. No seedlings were seen; so it is not known whether the young states have heterophyllous foliage like P. patulum or P. virgatum. Mr. Gibbs remarks that the large bracts present a somewhat conspicuous appearance, forming a kind of involucre surrounding the flower-heads. P. Dallii is evidently well worth cultivation as a garden-plant, and from the nature of its habitat will probably prove hardy all through the Dominion, and possibly in the south of England. The remarks made by Mr. Gibbs as to the fragrance of its flowers brings to mind the fact that P. Tobira, a native of Japan, is largely grown in France for the sake of its fragrant white flowers, which are sold in great quantities in the Paris flower-markets.