Succulent perennial or annual herbs, acaulescent or with nosose stems, roots fibrous or sometimes much thickened and tuber like; leaves alternate, flat, entire, parallel- veined, sheathing by a basal membranous and often closed sheath; inflorescence terminal, terminal and axillary, or less often axillary, a simple or compound helicoids cyme or thyrse, or the flower solitary, sometimes subtended by a boat-shaped spathe or foliaceous bracts; flowers usually actinomorphic, bisexual, the perianth of 2 series, the outer one a green herbaceous calyx  of 3 usually free and imbricated herbaceous sepals, the inner one a colored, corolla of 3 petals, stamens 6 but often the fertile ones reduced to 3 by abortion, the anthers with 2 parallel or divergent cells, dehiscing by longitudinal slits, filaments distinct, often bearded with colored moniliform hairs; pistil 1, the ovary superior, sessile 3 loculed, the ovules 1-few per cell and orthotropous, the placentation axile, style 1, stigma 1 and capitate or 3 fid; fruit a loculicidal capsule, sometimes enclosed by fleshy sepals, rarely fleshy and indehiscent; seeds with endosperm.