.jpg)
Manual of the New Zealand Flora.
1. Plagianthus, Forst
1. Plagianthus, Forst.
Trees or shrubs, rarely herbs. Leaves entire or lobed or serrate. Flowers usually small, hermaphrodite or unisexual, in axillary or terminal fascicles or panicles, or solitary. Bracteoles wanting, or small and distant from the calyx. Calyx 5-toothed or 5-fid. Staminal column split at the top into numerous filaments. Ovary 1-celled or 2–5-celled; ovules 1 in each cell; styles as many as the cells, clavate flattened or filiform, stigmatic along the inner side. Fruit of one or several carpels seceding from a common axis, indehiscent or splitting irregularly. Seed solitary, pendulous.
A small genus of about 12 species, confined to Australia and New Zealand, the species found in each country being endemic. The New Zealand species are practically diœcious, although a few hermaphrodite or female flowers are occasionally mixed with the males.
(Plagianthus Lyallii, Hook. f. Handb. N.Z. Flora, 30, is now referred to Gaya. P. linariifolia, Buch. in Trans. N.Z. Inst. xvi. (1884) 394, t. 34, is Coprosma Kirkii, Cheesem.)
Shrub, much branched. Leaves small, linear, entire. Flowers solitary or fascicled 1. P. divaricatus. Small tree. Leaves linear-oblong, toothed. Flowers in few-flowered cymes 2. P. cymosus. Tree, 30–60 ft. Leaves ovate or ovate-lanceolate, serrate. Flowers numerous, in decompound panicles 3. P. betulinus.
| 1. | P. divaricatus, Forst. Char. Gen. 86.—A glabrous much-branched shrub 4–8 ft. high; branches tough, slender, divaricating, often much interlaced. Leaves alternate or fascicled on short lateral branchlets; of young plants 1 in. long, linear-oblong, narrowed into rather long petioles, entire or sinuate; of mature plants ¼–¾ in., narrow-linear or narrow linear-obovate, coriaceous, obtuse, quite entire, 1-nerved. Flowers very small, generally unisexual, yellowish-white, solitary or fascicled, axillary; peduncles shorter page 77than the leaves. Calyx hemispherical, 5-toothed. Petals small, oblong-obovate, veined. Staminal tube with 8–12 large sessile anthers. Ovary 1-celled, rarely 2-celled; ovules 1 in each cell; styles the same number as the cells, clavate or flattened. Fruiting carpel about the size of a peppercorn, globose or rarely didymous, downy, bursting irregularly. Seeds solitary, or very rarely 2.—A. Rich. Fl. Nouv. Zel. 299; A. Cunn. Precur. n. 604; Raoul, Choix de Plantes, 48; Hook. Bot. Mag. t. 3271; Hook. f. Fl. Nov. Zel. i. 29; Handb. N.Z. Fl. 30; Buch. in Trans. N.Z. Inst. xvi. t. 34, f. 2; Kirk, Students' Fl. 70.
North and South Islands, Chatham Islands: Abundant in salt-water marshes from the North Cape to the Bluff. September–October. In the male flowers the ovary is smaller, almost rudimentary, and the style altogether enclosed within the staminal column; in the females the style is exserted, and the anthers are smaller and usually empty. |
| 2. | P. cymosus, T. Kirk, Students' Fl. 70.—A small closely branched tree about 20 ft. in height, glabrous except a few scattered stellate hairs on the young shoots and branches of the inflorescence. Leaves alternate or in alternate fascicles, ½–1¼ in. long, linear or linear-oblong or linear-obovate, obtuse or subacute, with a few deep serratures towards the tip; petioles slender, ¼–½ in. long. Flowers small, unisexual, in small axillary 5–15-flowered cymes, 1–1½ in. long, or in fascicles of 3–5, rarely solitary. Calyx campanulate, 5-toothed, narrower in the female flowers. Petals 5, ovate-spathulate or oblong-spathulate, much reduced in size in the females. Staminal column long and slender, with numerous anthers at the top. Ovary 1–2-celled; styles 1–2, clavate or broad and flattened. Fruiting carpels about ⅕ in. diam., didymous or globose, downy, seated in the persistent calyx.
North Island: Auckland—Kaitaia, Mongonui County, R. H. Matthews! South Island: Canterbury—Upper Waimakariri, alt. 2800 ft., J. D. Enys (Kirk, "Students' Flora"). Otago—Near Dunedin, G. M. Thomson! Petrie! October. A very peculiar plant, very distinct in habit and inflorescence, although the flowers closely agree in structure with those of P. betulinus, with the exception that the ovary is frequently 2-celled. It is remarkable that only one tree (a female) has been found in the Dunedin locality, and that only one (a male) is known at Kaitaia. The Waimakariri locality is given on the authority of Mr. Kirk. There are no specimens from thence in his herbarium. |
| 3. | P. betulinus, A. Cunn. Precur. n. 605.—A handsome leafy tree 30–60 ft. high, with a trunk sometimes 3 ft. in diam.; when young forming a straggling bush with interlaced tortuous branches. Bark exceedingly tough; branchlets, young leaves, petioles, and inflorescence more or less hoary with stellate hairs. Leaves of young plants small, ⅓–¾ in. long, broadly ovate or rounded to ovate-lanceolate, deeply and irregularly lobed or crenate-serrate. Leaves of mature plants 1–3 in. long, ovate or ovate-lanceolate, acuminate, coarsely crenate-serrate or doubly serrate, rounded or cuneate at page 78the base, membranous; petioles slender, ½–1 in. long. Flowers small, unisexual, very numerous, in terminal and axillary decompound panicles 4–9 in. long; pedicels slender. Calyx campanulate, 5-toothed. Petals oblong-spathulate, obtuse, clawed, much smaller in the female flowers. Staminal column exserted in the males, long and slender, bearing numerous almost sessile anthers at the tip. Fruiting carpels ⅙ in. diam., seated in the persistent veined calyx, ovoid, acuminate, downy. Seed solitary.—Raoul, Choix de Plantes, 48; Hook. f. Fl. Nov. Zel. i. 29; Handb. N.Z. Fl. 30; Kirk, forest Fl. t. 103, 104; Students' Fl. 71. P. urticinus, A. Cunn. Precur. n. 606. P. chathamica, Cockayne in Trans. N.Z. Inst. xxxiv. (1902) 319 (name only). Philippodendron regium, Poit. in Ann. Sc. Nat. ser. ii. viii. t. 3.
North and South Islands, Stewart Island, Chatham Islands: Lowland forests from Mongonui and Kaitaia southwards, but often local. Ascends to 1500 ft. November–December. Ribbon-wood of Europeans; manatu of the Maoris. Practically diœcious, although a few hermaphrodite flowers are sometimes mixed with the males. The male flowers are whitish-yellow, and are produced in immense profusion; the ovary is much reduced in size, and the style always included in the staminal column. The females are greenish, smaller and less numerous, the petals are smaller and adnate for some distance to the staminal column, the anthers are devoid of pollen, and the style exserted. Mr. Cockayne separates his P. chathamica on the ground of its not passing through a young stage with foliage differing from that of the mature tree. Flowering specimens from the Chatham Islands in my herbarium have rather larger calyces than the type, but I can see no other difference. For a full description of the seedlings and young plants of both forms, reference should be made to Mr. Cockayne's paper, "An Inquiry into the Seedling Forms of New Zealand Phanerogams and their Development, Part IV." (Trans. N.Z. Inst. xxxiii. 273–282). |