Bulbs seldom clustered, globose, 1-5 cm diam. Leaves usually fewer than 10, 1-6 dm × 4-20 mm. Inflorescences 20-80 cm; sterile bracts absent, bracts subtending flowers usually equaling or exceeding pedicel. Flowers usually zygomorphic, sometimes actinomorphic; tepals withering separately or connivent over capsules after anthesis, long-persistent on fruiting racemes, blue or bluish violet, each 3-9-veined, 12-35 × 1.5-8 mm; anthers usually yellow, sometimes bluish violet, violet, or brown, 2.5-7 mm; fruiting pedicel mostly incurving-erect, occasionally spreading-erect, 5-70 mm. Capsules not deciduous, pale green to pale brown, ovoid, 6-19 mm. Seeds 5-10 per locule. 2n = 30.
Camassia quamash is highly variable morphologically. Although there tend to be distinct geographical variants, here recognized as subspecies following F. W. Gould (1942), there is much overlap among them. The subspecific status of these taxa is retained to highlight the extreme morphological variability and geographical patterns within the species. A detailed biosystematic study of this complex is needed.