Perennial, rarely annual herbs, tufted or not, rhizomatous, stoloniferous, or cormous. Leaves mostly basal, distichous, linear or ensiform, sheathing at base. Flowers bisexual, actinomorphic or ± zygomorphic, in cymes, racemes or panicles, often densely villous. Perianth persistent, petaloid, segments 6 in 2 series, tube short to long, or 0. Stamens 6 or 3; filaments free; anthers 2-locular, opening by longitudinal slits. Ovary superior to inferior, 3-locular; style usually filiform; stigma capitate, minute, or stigmas 3; ovules 1-many in each locule. Fruit a 3-valved loculicidal capsule. Genera c. 14, mainly of S. Hemisphere.