Annual, biennial or perennial herbs, caulescent or acaulescent, sometimes almost shrubby. Lvs alternate or in basal rosettes, simple and entire to pinnatisect or 2-pinnate. Fls in terminal leafy spikes, 1 or few in axils of subtending lvs. Axis of fl. produced well beyond ovary to form a prominent deciduous floral tube. Sepals 4, reflexed at anthesis, sometimes white to red. Petals 4, generally large (> 10 mm long), usually yellow, white or pink. Stamens 8, equal or the 4 outer or antisepalous ones longer; anthers usually versatile and not erect. Ovary 4-celled; stigma capitate to 4-lobed. Capsule loculicidal, 4-valved, ± elongated, membranous to woody, free or fused with subtending bract, sometimes winged. Seeds numerous, often angular, occasionally winged.