Trianthema

Mostly succulent, annual herbs, rarely undershrubs, usually diffuse or prostrate. Leaves opposite, glabrous, papillose or hairy, with membranes or stipule-like lobes at base of petioles. Flowers bisexual, axillary, solitary or in fascicles, cymes or clusters, with 2 bracteoles each. Perianth 5-lobed; tube short or subelongated and campanulate; lobes small or large, with membranous margins, coloured within, dorsally mucronate. Stamens 5-many, sometimes unequal, separate or grouped, arising from base of calyx lobes; filament filiform; anthers small, rotund to oblong. Ovary superior, with 1 carpel, 1-locular; ovules 2-many, campylotropous; placentation basal or parietal; style 1(2), short; stigma longitudinal, papillate. Fruit a membranous or coriaceous capsule, transversely dehiscent. Seeds 1 or 2, round-reniform, arillate, reddish brown to black; embryo annular to coiled; cotyledons oblong, fleshy; endosperm starchy. x= 7, 8, 13 (polyploidy).