Bulbs ovoid, 5-7 cm, tunic reddish to brown, membranous, outer scales with few delicate fibers. Leaves 1-3 dm × 4-12 mm, margins strongly undulate. Panicles 3-10 dm, branches ascending. Flowers vespertine, closed by following morning; tepals recurved at anthesis, white with purplish midvein, linear, 1.5-3 cm; stamens typically slightly shorter than tepals; anthers yellow, 3 mm; pollen yellow; style often exserted after anthesis, 12-28 mm, equal to or slightly longer than tepals; pedicel stout, 2-5 mm, much shorter than perianth. Capsules 5-8 mm.

Flowering May--Jun. Among rocks (usually serpentinite) on open brushy or wooded hills; of conservation concern; 300--500 m; Calif.

Chlorogalum grandiflorum is considered by the California Native Plant Society to be endangered in a portion of its range. It is often confused with C. pomeridianum var. minus because of bulb characters, but it can be distinguished by its short, stout pedicels and larger flowers.