Description from Flora of China
Castanola Llanos; Hamiandrina J. D. Hooker; Troostwykia Miquel.
Lianas or scrambling shrubs. Leaves alternate, exstipulate, petiolate, 3-foliolate. Inflorescences axillary, pseudoterminal, or terminal, paniculate, usually some of main branches subequal; bracts and bracteoles persistent; bracts terete, slightly thickened at apex; bracteoles narrowly linear. Flowers bisexual, (4 or)5-merous. Sepals imbricate in bud, minutely tomentose or rather sericeous abaxially, shortly appressed pubescent adaxially, inner ones longer, overlapping margins paler, glandular ciliate. Petals linear, distinctly longer than sepals, glabrous. Stamens usually (5 or)10(or 15), alternately longer and shorter, those opposite sepals longer than those opposite petals (which are rarely absent); filaments slightly connate at base. Carpels 5, sometimes some sterile; ovary hairy; ovules 2, erect, collateral. Style cylindric, base hairy; stigma globose, 3-lobed, minute. Follicle red when ripe, pyriform, usually strongly recurved, often tuberculate, ± densely tomentose, dehiscing by a longitudinal slit, with persistent but not enlarged calyx, base contracted, apex rounded; pericarp rather thin. Seed 1, black, glossy, covered by orange or yellow aril; endosperm absent.
Between seven and 50 species: tropical Africa to SE Asia; one species in China.