The Punui, one of the most striking plants in the New Zealand flora, was discovered by Dr. Lyall in 1848, and referred by Dr. Hooker** to Aralia polaris, Homb. and Jacq., discovered by those botanists on the Auckland Islands in 1839. Subsequently Dr. Hooker's suggestion that Aralia polaris might form a new genus to be termed Stilbocarpa was carried out by Decaisne and Planchon, and in the Handbook of the New Zealand Flora published in 1864, the Auckland and Stewart Island plants are included under the description of Stilbocarpa polaris, Decn. & Plan., the author stating that Lyall's plant wants the long bristles which are so characteristic of the Auckland Island plant, and might belong to another species††
For the sake of conciseness, in the following paragraphs the native name punui will be restricted to the Stewart Island plant; the generic name Stilbocarpa to that from the Auckland Islands.
Until recently so little has been known of the flora of Stewart Island that, notwithstanding the botanical interest attached to such a remarkable plant as the punui the material for determining its precise relationship to Stilbocarpa has not been available: no specimens were to be found in our Herbaria, no plants in our botanic gardens. In 1878 a fine living specimen
[Footnote] * Fl. N.Z. i., p. 95.
[Footnote] † Handbook N.Z. Flora, p. 100.
with other Stewart Island plants was kindly placed at my disposal by Mr. C. Traill, who shipped them by the Government steamer “Stella,” which also brought several cases of plants from the Auckland Islands for the Colonial Botanic Gardens. As my case was by some mistake removed to the gardens, I allowed the plants to remain there, so that the punui was grown under the same conditions as the Stilbocarpa, all the plants at first being planted in the shade-house.
While closely agreeing in the shape of the leaf, toothing, venation, etc., the two plants exhibited marked differences in minor characters—the texture of the leaf, amount of hairiness, and the colour and size of the hairs: the leaves of the punui being more membranous than those of the Stilbocarpa, the upper surface usually glabrous, the lower clothed with soft white hairs and the terete petiole. In Stilbocarpa both surfaces were clothed with fulvous bristly hairs, longer and stouter than those of the punui, the petiole was slightly compressed, and in some cases faintly grooved on the upper surface. In both plants the petiole was pilose.
Two specimens of Stilbocarpa gradually developed new leaves in which the texture was less coriaceous, and the hairs reduced in number, shorter, and less bristly. These were exactly the results which I had observed in a greater degree with plants cultivated for two years in my own garden, so that the theory which attributed the trivial differences between the vegetative organs of the two plants to the different climatal conditions under which they grew, seemed to receive all the confirmation needed to establish their identity. Had good specimens of the flowers and fruit been available for examination, the opinion expressed by me** would have been different. Business, however, took me from Wellington before the punui had fairly developed flowers, and the single imperfect specimen that I was able to secure exhibited no characters calculated to alter my opinion.
In 1880 Mr. J. B. Armstrong gave an imperfect description of the punui under the name of Stilbocarpa lyallii.†† He states, “unfortunately I have not been able to obtain flowers or fruit, but there is no doubt as to the genus,” and describes the leaves as being “from 4 to 8 inches across or more, with a closed—not open—sinus.” As will be shown presently, both these statements are erroneous.
Recently I have had the pleasure of examining the punui in its native island, and have received fully ripe fruit from Mr. C. Traill, the result being that not only must my old opinion as to its identity with Stilbocarpa polaris be abandoned, but that it must be removed to another genus.
[Footnote] * “Trans. N.Z. Inst.,” vol. xiv., p. 387.
[Footnote] † “Trans. N.Z. Inst.,” xiii., p. 336.
Stilbocarpa was proposed by Sir Joseph Hooker as the name of a mono-typic genus, consisting of the Auckland Island plant already mentioned, and was established by Decaisne and Planchon in 1854, its essential characters being drawn from the 3–4-celled acetabuliform fruit, which in fact affords almost the only characters by which it can be separated from Aralia. The fruit of the punui, instead of exhibiting the cup-shaped cavity characteristic of Stilbocarpa, has a flattened apex covered with an epigynous disc consisting of the two stylopodia: in all respects agreeing with Aralia, to which it must consequently be removed, and in honour of its discoverer may worthily be designated A. lyallii. I now append a description.