秋海棠科

Ching-I Peng

Begonia austrotaiwanensis Credit: Ching-I Peng

Perennial succulent herb, very rarely subshrub. Stem erect, stoloniferous rarely climbing or often only with rhizome; rhizome spheroidal, tuberous, terete or long terete and moniliform; mostly erect, transverse or stoloniferous. Leaf simple, rarely palmately compound, alternate or all basal; with petiole, stipules deciduous; leaf blade often oblique irregularly serrate and divided, occasionally entire; venation usually palmate. Flowers unisexual, monoecious, occasionally dioecious (1–)2–4 to several rarely numerous in dichotomous cyme, sometimes panicle, with pedicel and bracts; tepals petaloid, staminate flower: tepals 2–4, valvate or 4 decussate, usually the outer ones longer, the inner ones smaller; stamens numerous, filaments free or only connated at base; anthers 2-celled, apical or lateral, connective apex extended, apiculate. Pistillate flower: tepals 2–4(–5–8) free; ovary inferior 1–2–3 rarely 4 or 5–7 locular; placentas central or parietal, stigma turgid, spirally twisted-tortuous or U-like, capital or reniform and setose-papillose. Capsule dry, sometimes berry-like, usually unequally rarely subequally 3-winged rarely wingless and 3–4-horned; seeds very numerous, minute, oblong, pale brown smooth or reticulate testa.

Three genera and more than1400 species, widely distributed in the tropical and subtropical regions of the world; one genus in Taiwan.

Lower Taxon

• Begonia Linn.