Trailing to erect, perennial succulent shrubs. Lvs opposite, sessile, 3-angled to terete, entire or denticulate, smooth or papillate; papillae not glittering. Fls usually in terminal or axillary cymes, or sometimes solitary, pedicellate, usually with leaflike bracts. Sepals 5, unequal: 2 triangular, acuminate, 3 smaller with expanded membranous margins. Petals numerous, > sepals, free; stamens numerous; staminodes 0. Placentation parietal. Stigmas (4)-5-(7), plumose. Capsule (4)-5-(7)-locular; expanding keels divergent; wings present; locules with lids; placental tubercle 0. Seeds obovoid, weakly compressed, rugose.