Flora of New Zealand Series

Type: In the Cockayne herb. in W, I have found only one specimen collected by Cockayne on Chatham Id. This is labelled "Plagianthus chathamicus Cockayne. Juvenile shoot from young plant in moist Te Awa Tapu Forest, Chatham Island. Coll. L. Cockayne, Feb. 1901."

Plant not heteroblastic; lvs of young plants on petioles c. 2 cm. long; lamina 5-10 × 4-7 cm., very deeply irregularly crenate-serrate, ± 3-lobed, similar to that of adults; subfloral lvs ± ovate, c. 3 × 2 cm.; calyx sts up to 5 mm. long.

DIST.: Chatham Is.

Cockayne (T.N.Z.I. 33, 1901, 275) gives a full account of seedlings and young plants grown from the Chatham Id variety. He says: "The similarity of appearance in form between the seedlings and adult leaves . . . was pointed out to me . . . by Mr. S. D. Barker." He was advised by Mr. F. A. D. Cox that the Chatham Id plant "certainly does not pass through the stages you have mentioned; as far as I have observed branches and twigs are always upright, as in the mature form, and leaves always the same shape." Later (T.N.Z.I. 34, 1902, 319) he gives the name P. chathamicus sp. nov., with the remark: "I have separated this plant from P. betulinus because they differ in the seedling state, and P. chathamicus is also never furnished with reversion shoots."

P. urticinus A. Cunn., loc. cit., is given as a shrub 6-8 feet tall. Cunningham remarks: "This species differs from [P. betulinus] in its leaves being smaller and more attenuated, in having its branchlets more hoary, and its petals, which are united almost at the base of the tube of stamens, more attenuated and somewhat exceeding the tube in length, within which the style is, moreover, wholly inclosed." The locality is given as: "Among underwood on the banks on the Kana-Kana river, Bay of Islands.-1826, A. Cunningham." Kirk (For. Fl. 1889, 207) remarks: "A. Cunningham described one of the forms as a distinct species under the name of P. urticinus; but it cannot be separated [from P. betulinus] even as a variety." Cheeseman (Man. N.Z. Fl. 1925, 563) places the name as an absolute synonym of P. betulinus, but further study seems desirable.