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. 2 n = 24. Flowering mid spring; fruiting early summer. Barren shales that are heavily gypsiferous or otherwise chemically unusual (borate-bearing, lithium-bearing), creosote bush zone; of conservation concern; 500-1000 m; Ariz., Nev., Utah. 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.

Plant: perennial herb; forming rounded clumps, 2.5-6 dm tall, with a branching caudex, this clothed with ash to straw colored marcescent leaf bases Leaves: 5-14 cm long, 3-25 mm wide, cuneate, usually apically 3-5-toothed or -lobed, each tooth or lobe with an acerose bristle 4-8 mm long, densely clothed with strongly ascending barbellate trichomes to ca. 10 mm long INFLORESCENCE: paniculiform cymes 10-30 cm long, with 5-20 flowers; peduncles mainly 7-17 cm long, often with 1 or 2 foliose bracts Flowers: 1.5-4 cm across, nodding in bud; sepals 2 or 3; petals 4 or 6; stamens many; styles lacking or less than 1.5 mm long; stigmas connate, 3-6; sepals 3, 8-15 mm long; petals yellow Fruit: capsules obovoid to obconic, 12-23 mm long, 7-10 mm wide. SEEDS shiny-black, 2.5-3 mm long, ca. 1.2 mm thick, conspicuously strophiolate. Misc: Heavily gypsic substrates in desert shrub communities not dominated by Larrea; 550-950 m (1800-3100 ft); Mar-May REFERENCES: Ownbey, Gerald B., Jeffrey W. Brasher, and Curtis Clark. 1998 Papaveraceae. J. Ariz. – Nev. Acad. Sci. 30(2): 120.