Trianthema
12 species in Aust. (10 endemic); Qld, NSW, NT, S.A., WA
Prostrate to ascending annuals or perennials. Leaves opposite, ± unequal in each pair, sheathing at the base. Flowers solitary or clustered, sessile. Perianth lobes 5, white to pink, unequal. Stamens adnate to perianth. Ovary superior, 1-locular; placentas basal; style solitary. Capsule circumscissile near the base.