Stems slender, 2-5 dm. Leaves: basal withering, 1-2 dm; blade linear. Inflorescences subumbellate, 1-4-flowered; bracts 1-8 cm. Flowers erect; perianth open, campanulate; sepals lanceolate-oblong, attenuate, 2-3 cm; petals deep yellow, usually streaked red-brown proximally, often with median red-brown blotch, cuneate to obovate, 2-4 cm, with a few slender hairs near gland; glands ± lunate to oblong, not depressed, covered with short, matted hairs; filaments 7-9 mm; anthers linear-oblong, 4-6 mm, apex obtuse or acute. Capsules erect, lanceoloid-linear, angled, 3-6 cm. Seeds light beige, flat. 2n = 14, 28. Flowering late spring--mid summer. Heavy soils in grasslands, open woodlands, mixed evergreen forests; 0--700 m; Calif. Coastal plants of Calochortus luteus are mostly triploid, while those of the interior are mostly diploid. Occasionally this species hybridizes with C. superbus.