Panicle usually branched nearly to tip, ± loosely flowered; bracts in unbranched portion ovate-elliptic, mostly less than 1 cm, shorter than flowers. Tepals elliptic to oblong-ovate, 8-15 mm. 2n = 32.
Flowering summer--early fall. Moist to wet, marshy sites; 1000--3500 m; Ariz., Calif., Colo., Idaho, Nev., N.Mex., Oreg., Utah, Wash., Wyo.
Smaller-flowered plants from Colorado and New Mexico have been called Veratrum tenuipetalum; except for flower size, which is at the lower end of the species range, these plants are congruent with V. californicum var. californicum.
N. Chiariello et al. (1980), using the snow-bank-emergent characteristics of Veratrum californicum, documented that the plants differing in open versus closed bud morphologies also have different leaf areas, internal temperatures, and rates of early expansion growth. These differences in life-history characteristics are inferentially similar to those of other alpine and northern Veratrum species.