Perennial or annual, terrestrial or epiphytic usually rhizomatous herbs. Roots fibrous or tuber-like. Usually rhizome present. Leaves spiral, opposite or whorled on the aerial stem or in basal rosettes; sessile or ± petiolate, with or without sheathing base, lamina entire, ovate to linear, rarely sagittate, with few prominent parallel veins. Inflorescence racemes or spikes or borne in axillary clusters on a leafy stem. Flowers bisexual, actinomorphic, hypogynous or epigynous. Tepals usually 3 + 3, commonly all similar, gamophyllous, tubular below, lobes free.. Stamens usually 6, filaments free or epiphyllous, commonly inserted in the upper part of the tube; anthers basifixed or dorsifixed, dehiscence longitudinal. Pistil tricarpellary, syncarpous, usually trilocular, placentation axile or basal, ovule 2-many per locule, style simple, stigma capitate or 3-lobed. Fruit usually a berry or capsule rupturing irregularly. Seeds sometimes with a showy sarcotesta.