Rootstocks tuberous, or a coated corm. Leaves
radical, lanceolate and plaited, or linear and flat, petioled. Inflorescence
spicate, or racemed, or subcapitate, scape short or long. Flowers often
unisexual, perianth limb sessile or very shortly stipitate above the ovary.
Stamens 6, on the base of the segments, filaments short, anthers erect,
dorsifixed. Ovary 3-celled, style short, columnar, stigmas 3, erect, stout,
distinct or connate, ovules 2-seriate. Fruits indehiscent, usually more or less
beaked. Seeds black.