Plants subscapose, to 6 dm. Leaves 3-20 cm; blade shallowly to deeply 3-7-lobed distally, 5 cm wide distally, copiously long-pilose, sometimes also minutely hirsute. Inflorescences 3-20-flowered, branching, glabrous throughout or long-pilose proximally; buds glabrous. Flowers: sepals glabrous; petals caducous, 6, deep yellow, 2.5-4 cm; filaments not dilated distally; style absent. Capsules persistent, obconic, 1-2.5 cm, dehiscing not more than 1/4 length. 2n = 24.
Phenology: Flowering mid spring; fruiting early summer.
Habitat: Barren shales that are heavily gypsiferous or otherwise chemically unusual (borate-bearing, lithium-bearing), creosote bush zone
Elevation: 500-1000 m
Ariz., Nev., Utah.
Of conservation concern.
Arctomecon californica is found in mostly small populations ranging from the vicinity of Las Vegas, Nevada, eastward to extreme northwestern Arizona near Lake Mead. It is known otherwise only from a single collection in Washington County, Utah.