Delphinium hesperium subsp. pallescens
Brittonia 8: 10. 1954.
Stems usually glabrous. Inflorescences usually fewer than 25-flowered, open; pedicel ± spreading. Flowers: sepals white to pinkish, rarely light blue, spreading, lateral sepals 10-15 mm, more than 4 mm wide, spurs 10-17 mm; lower petal blades 4-7 mm. Fruits 3-3.5 times longer than wide. 2n = 16.
Phenology: Flowering spring.
Habitat: Open oak woods and grassland
Elevation: 20-1000 m
Delphinium hesperium subsp. pallescens grows only east of the Coast Range divide. It hybridizes with D. gypsophilum, D. parryi, D. recurvatum, D. uliginosum, and D. variegatum. Light blue sepals probably result from introgression involving D. variegatum, D. parryi, or D. hesperium subsp. hesperium. Intermediates are occasionally found between D. hesperium subsp. pallescens and subsp. hesperium (particularly in Napa County), but the two taxa remain, for the most part, geographically isolated.
Delphinium hesperium subsp. pallescens has sometimes been confused with D. gypsophilum or with white-flowered plants of D. hansenii; see discussion under those species.