Description from Flora of China
Trianthema monogynum Linnaeus.
Herbs perennial. Stems procumbent, subterete or slightly angular, glabrous or sparsely hairy when young. Petiole 4-30 mm, base expanded into sheath 2-2.5 mm; leaf blade elliptic to ovate, obovate, or obcordate, 8-50 × 4-45 mm, thinly fleshy, base cuneate, apex obtuse, retuse, truncate, or slightly acute. Flowers solitary, sessile. Perigone lobes usually 5, inside mostly pale pink, rarely white, 4-5 mm; perigone tube fused with basal sheath of pedicel, forming a funnel; lobes rather obtuse, with an apical spur. Stamens 10-25. Stigma 1, ca. 3 mm. Capsule truncate at apex, 2-lobed, operculum fleshy, base thinly walled. Seeds several, black, reniform, 1-2.5 mm, broad, with low crests. Fl. summer. 2n = 26, 28, 56.
Open sunny dry sands, usually near sea or as weeds in fields. Guangdong, Hainan (including Nanhai Zhudao), Taiwan [pantropical].