Bulbs 7-15 cm, tunic thick, with numerous coarse, brown fibers of old bulb scales (except var. minus). Leaves 2-7 dm × 6-25 mm, margins usually strongly undulate. Panicles 3-25 dm, branches many. Flowers vespertine, open 1 night only, closed by next morning; tepals spreading and recurved at anthesis, white with green or purple midveins, linear, 1.5-2.5 cm; stamens shorter than tepals; anthers purple or yellow, ca. 3 mm; pollen yellow or whitish; style 10-15 mm, from shorter to longer than tepals; pedicel slender, 5-35 mm, usually ca. equal to or exceeding perianth. Capsules 5-7 mm.