Fls us. solitary, regular, 4-merous; perig. with very short calyx-tube; petals us. 2-lobed; stamens 8, in 2 series; ovary 4-celled, ovules ∞; stigma capitate to 4-lobed. Fr. a long narrow capsule with loculicidal dehiscence; seeds mostly papillose, with a chalazal brush of hairs (coma). Herbs or subshrubs with at least lower lvs opp. Some 200 spp., mainly of temperate regions.

n = 18

n = 18

n = 18

Erect or creeping herbs, usually perennial, very rarely annual, sometimes woody near base, overwintering and multiplying by leafy rosettes, subterranean or surface runners and stolons, turions or gemmae. Lvs opposite, at least below infl., often lower opposite and upper alternate, occasionally all alternate, rarely verticillate, simple. Fls solitary in lf axils, but sometimes forming a ± definite, terminal, racemose infl., usually actinomorphic, occasionally somewhat zygomorphic; pollen and stigmas ripening together, occasionally markedly protogynous or protandrous. Buds erect to pendulous. Floral tube present or 0, cylindric. Sepals 4, caducous. Petals 4, nearly always white or cream to pink, rose or purple, usually emarginate, sometimes entire, not clawed. Stamens 8, the outer whorl longer; anthers basifixed or dorsifixed. Stigma capitate, clavate, or deeply 4-lobed. Capsule 4-celled, loculicidal, slender. Seeds usually numerous, ± brown, nearly always with terminal, caducous or persistent coma of silky hairs.