Manual of the New Zealand Flora.
Order XVIII. Rhamneæ
Order XVIII. Rhamneæ
Trees, shrubs, or woody climbers; branches sometimes spinescent. Leaves simple, alternate, rarely opposite, entire or toothed. Stipules small, often caducous, sometimes metamorphosed into thorns. Flowers regular, hermaphrodite or unisexual, small and inconspicuous, usually arranged in axillary or terminal cymes or panicles. Calyx 4–5-cleft, valvate. Petals 4–5, rarely wanting, inserted on the throat of the calyx-tube, small, usually hood-shaped or involute. Stamens 4–5, perigynous, inserted with the petals and opposite to them; filaments short; anthers often concealed within the involute tips of the petals. Disc perigynous, adnate to the calyx, of very various shape. Ovary free or immersed in the disc, altogether superior or more or less adnate to the calyx-tube, 3-celled, rarely 2- or 4-celled; style short; ovules solitary in each cell, erect, anatropous. Fruit free or girt by the persistent calyx-tube, drupaceous or capsular, 1–4-celled. Seed solitary, erect, sometimes arillate; albumen fleshy, rarely wanting; embryo large, erect, radicle inferior.
A well-marked order, distributed over most parts of the world. Genera about 40; species under 500. The jujube (Zizyphus) produces a wholesome and agreeable fruit, but as a rule most of the species possess bitter or astringent properties, and some are purgative. The 2 genera found in New Zealand both extend to Australia, and 1 of them (Discaria) is found in South America as well.
Tomentose, unarmed. Leaves alternate. Ovary inferior 1. Pomaderris. Glabrous, spiny. Leaves opposite or wanting. Ovary superior 2. Discaria.
1. Pomaderris, Labill.
Shrubs, more or less covered with hoary or ferruginous stellate tomentum. Leaves alternate. Plowers pedicellate, in small cymes usually forming terminal or axillary corymbs or panicles. Calyx-tube adnate to the ovary, limb 5-toothed to the base, deciduous or reflexed. Petals 5 or wanting. Stamens 5; filaments longer than the petals; anthers oblong. Disc inconspicuous, surrounding the top of the ovary at the base of the calyx-lobes. Ovary more or less inferior; style 3-fid. Capsule small, upper part protruding above the calyx-tube, 3-valved; endocarp separating into 3 cocci, which either split down the inner face or open by an oblong lid. Seed on a thickened funicle.
A genus of about 22 species, restricted to Australia, New Caledonia, and New Zealand. Three of the New Zealand species are also found in Australia; he fourth is endemic.
* Flowers with petals.
Leaves 2–3 in., elliptic-oblong, obtuse, entire 1. P. elliptica. ** Flowers without petals.
Leaves 2–4 in., oblong-ovate, crenulate; tomentum white or grey 2. P. apetala. Leaves ¾–2 in., oblong or oblong-lanceolate; tomentum often ferruginous 3. P. Edgerleyi. Leaves small, linear or oblong, ⅛–¼ in., margins revolute to the midrib 4. P. phylicæfolia.
2. Discaria, Hook.
Much-branched rigid shrubs or small trees, with opposite often spinous branchlets. Leaves opposite or fascicled, sometimes wanting. Flowers axillary. Calyx membranous, free or adnate to the ovary at the base; limb campanulate, 4–5-lobed. Petals 4–5, hooded, often wanting. Stamens 4–5; filaments short. Disc adnate to the base of the calyx-tube, annular. Ovary more or less sunk in the disc, 3-lobed, 3-celled; style slender; stigma 3-lobed. Drupe (or capsule) dry, coriaceous, 3-lobed, endocarp separating into 3 2-valved crustaceous cocci. Seeds with a coriaceous testa.
Species about 16, mostly natives of extratropical and alpine South America, with 1 species in Australia and another in New Zealand.
1. | D. Toumatou, Raoul, Choix de Plantes, 29, t. 29.—A much-branched thorny bush or small tree 2–15 ft. high or even more, glabrous or slightly puberulous. Branches divaricating, flexuous; young ones green, terete; branchlets reduced to opposite distichous or decussate rigid spines 1½–2 in. long. Leaves often wanting, fascicled below the axils of the spines or opposite on short shoots, ½–¾ in. long, linear-obovate or oblong-obovate, obtuse. Flowers small, ⅙ in. diam., greenish-white, fascicled with the leaves below the axils of the spines; pedicels short, puberulous. Calyx-lobes 4–5, reflexed. Petals wanting. Capsule ⅕ in. diam., globose, deeply 3-lobed.— Hook. f. Handb. N.Z. Fl. 44; Kirk, Forest Fl. t. 136; Students' Fl. 93. D. australis, Hook., var. apetala, Hook. f. Fl. Nov. Zel. i. 47. Notophœna Toumatou, Miers in Ann. & Mag. Nat. Hist. Ser. iii. v. (1860) 271. North and South Islands: Waikato River to the Bluff, common. Ascends to 3500 ft. [ unclear: Tumætukuru.]. November–January. Can only be distinguished from the Australian and Tasmanian D. australis by the absence of petals. It attains a large size in the cool mountain-valleys of the South Island, but near the coast is usually low and scrubby. |