Madroño 22: 100, fig. 1. 1973.
Stems usually branching, 1–6 dm. Leaves: basal persistent, 1–7 dm; blade lanceolate, flat. Inflorescences 2–several-flowered. Flowers erect; perianth open, campanulate; petals light yellow-green, flecked and streaked purplish brown, oblanceolate, ciliate to near apex, hairy; glands depressed, bordered proximally by ciliate membrane, distally by 2 or more rows of short hairs; anthers short-tipped. Capsules erect, angled, apex acute. Seeds dark brown, irregular. 2n = 20.
Phenology: Flowering late spring–early summer.
Habitat: Serpentine grasslands
Elevation: 0–200 m
Of conservation concern.
Calochortus tiburonensis is known only from Ring Mountain, Marin County.