Mariposa lutea (Douglas ex Lindley) Hoover

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.