Caudex a thickened crown, branched. Stems several from base, exserted to nearly covered with basal leaves (densely clustered), erect or decumbent. Basal leaves: blade margins sinuate-dentate or entire. Fruits (strongly latiseptate), compressed at margins and apex, apex (acute), often beaked; valves pubescent inside; ovules 4 per ovary; style frequently curved. 2n = 10.

Flowering (Apr-)Jun-Aug. Loose gravelly soils, talus slopes, volcanic rocks, rocky ridges, metamorphic rubble, marbleized rocks, decomposed limestone and schist, barren hillsides, whitish ash deposits; (600-) 1800-3400 m; Calif., Idaho, Nev., Oreg., Wash.