Sometimes included in Liliaceae.
Habit and leaf form. Herbs (tufted, aerial stems erect, simple or with a few long branches, leafless or a short leaf under the lowest branch); evergreen, or deciduous. Perennial. Leaves basal. 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; 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; grass-like; parallel-veined; without cross-venules; sheathing, scarious. Leaves ligulate, or eligulate; without stipules. Leaf blade margins entire. 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 (simple), or in panicles. The terminal inflorescence unit cymose, or racemose (simple or compound). Inflorescences scapiflorous; terminal; with involucral bracts, or without involucral bracts; pseudanthial, or not pseudanthial. Flowers pedicellate (articulated at or near the middle, close to the flower); bracteate (distant, scarious, enclosing 1–3 flowers); ebracteolate; small, or medium-sized; regular; 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; purple (to blue), or blue (pale to dark, or lilac). Perianth members fringed (inner segments, or sometimes crisped). 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 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; on the base of the perianth, almost hypogynous; alterniperianthial, or oppositiperianthial. Filaments hairy. Anthers dorsifixed, or basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged (2 or 4, crest-like, densely hairy, basal, reflexed on the filament). 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. Placentation axile. Ovules 1–6 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; several per cell. Seeds endospermic. Cotyledons 1. Embryo straight to curved.