ovule solitary, basilar, erect. Fruit a utricle with a membranous pericarp, firmly enclosed in the thickened or hardened base of the perianth-tube, which falls off with it. Seed erect, with a thin adherent testa; albumen farinaceous or fleshy; embryo with foliaceous cotyledons usually wrapped round the albumen, radicle inferior.
A small order, of no economical importance, with the exception of 2 or 3 wide-ranging genera almost wholly confined to tropical America. Genera 23; species about 200. The single New Zealand genus is distributed over the shores of most tropical countries.
1. PISONIA, Linn.
Trees or shrubs, usually unarmed, rarely spinous. Leaves opposite or scattered. Flowers unisexual or hermaphrodite, small, 2–3-bracteolate at the base, usually arranged in lax or dense cymose panicles. Perianth of the male flowers funnel-shaped or almost campanulate, of the females tubular, sometimes swollen at the base; limb 5-toothed; teeth short, induplicate-valvate, erect or patent. Stamens 6–10; filaments unequal, connate at the base into a tube or ring; anthers oblong or didymous, exserted or included. Ovary elongated, narrowed into a slender included or exserted style; stigma obliquely capitate or dilated, often fimbriate. Fruiting perianth elongated or oblong, 5-ribbed or cylindrical, smooth or glandular-muricate, usually viscid, firmly enclosing the membranous utricle. Seed solitary, oblong, longitudinally grooved; embryo straight, the cotyledons convolute, enclosing the scanty albumen.
A large genus in tropical and subtropical America, with a few species in southern Asia, Australia, Polynesia, and the Mascarene Islands. The New Zealand species occurs in Norfolk Island and Australia, and may possibly have a wider range.
1. P. Brunoniana, Endl. Prodr. Fl. Norfl. 43.—A glabrous shrub or small tree, usually 12–20 ft. high, but sometimes attaining 35 ft. with a trunk 2 ft. in diam.; wood soft, brittle. Leaves usually opposite, but often irregularly alternate or sometimes approximate in threes, petiolate, 4–15 in. long, oblong to ovate-oblong or elliptic-oblong, obtuse or subacute, quite entire, membranous and flaccid when young, but becoming firm in age. Cymes much branched, terminal, many-flowered. Flowers usually hermaphrodite, but sometimes the stamens are abortive. Perianth ⅕ in. long, greenish, glabrous or puberulous, funnelshaped with a campanulate mouth. Stamens 6–8; anthers equalling the perianth or slightly exserted. Fruit 1–1¼ in. long, linear, narrowed above, 5-ribbed; ribs minutely papillose, extremely viscid.—Handb. N.Z. Fl. 229; Benth. Fl. Austral. v. 280; Kirk, Forest Fl. t. 140. P. Sinclairii, Hook. f. Fl. Nov. Zel. i. 209, t. 50. P. Mooreiana, F. Muell. Fragm. i. 20.
