Sometimes included in Liliaceae.
Habit and leaf form. Herbs (tufted, aerial stems erect, condensed or leafy and then bearing the inflorescence); evergreen, or deciduous. Perennial. Leaves basal, or cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; rhizomatous, or tuberous (may also lack a perennating organ). Self supporting, or climbing. Mesophytic, or xerophytic. Leaves alternate (crowded at the base of the stem usually in a rosette); spiral, or distichous; ‘herbaceous’, or leathery, or membranous; sessile; sheathing. Leaf sheaths not tubular; with free margins. Leaves edgewise to the stem, or with ‘normal’ orientation; simple. Leaf blades entire; flat, or folded, or solid (or triquetrous); linear, or lanceolate, or oblong, or ovate; linear (grass-like); veins prominent; without cross-venules; sheathing. Leaves ligulate, or eligulate; without stipules. Leaf blade margins entire (often fringed). Leaf anatomy. Hairs absent. Extra-floral nectaries absent. Stem anatomy. Secondary thickening absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the gynoecium (from septal nectaries).
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes, or in panicles, or in fascicles (or clusters). The terminal inflorescence unit cymose, or racemose (simple or compound). Inflorescences scapiflorous; terminal, or axillary; inflorescence axis simple or few branched; inflorescence more or less arching ascending; 1–6 flowers in discrete clusters; with involucral bracts, or without involucral bracts; pseudanthial, or not pseudanthial. Flowers pedicellate (articulate near the middle, below the middle); bracteate (flower clusters and a few small bracts in the axils of larger bracts, ovate, attenuate, scarious); small, or medium-sized; very irregular; 3 merous; cyclic; pentacyclic, or tetracyclic. Perigone tube absent. Perianth with distinct calyx and corolla (the whorls rather different), or of ‘tepals’; 6; 2 -whorled (3+3); isomerous; free; petaloid; similar in the two whorls, or different in the two whorls; white, or pink. Calyx (if the outer whorl so interpreted) 3; 1 -whorled; regular. Corolla (if the inner whorl so interpreted) 3; 1 -whorled; regular. Corolla members sometimes fringed. Androecial members definite in number. Androecium 6. Androecial members free of the perianth, or adnate; all equal; free of one another; 1 -whorled, or 2 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 3. Stamens 6; all more or less similar in shape; isomerous with the perianth, or diplostemonous; all hypogynous or 3 hypogynous and 3 attached to the base of the inner segments; alterniperianthial, or oppositiperianthial. Anthers basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 3 carpelled. The pistil 3 celled. Carpels isomerous with the perianth. Gynoecium syncarpous; synstylovarious, or eu-syncarpous; superior. Ovary plurilocular; 3 locular; sessile. Gynoecium stylate. Styles 1; apical (or nearly so). Stigmas 1; 2–3 - lobed; capitate. Placentation axile. Ovules 2–30 per locule; arillate, or non-arillate; campylotropous (generally), or anatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; usually a capsule. Capsules loculicidal. Fruit 3 celled; few per locule. Seeds endospermic. Cotyledons 1. Embryo straight to curved.