39c. Delphinium hesperium subsp. pallescens (Ewan) H. F. Lewis & Epling, Brittonia. 8: 10. 1954.
Pale-flowered western larkspur
Delphinium hesperium A. Gray forma pallescens Ewan, Univ. Colorado Stud., Ser. D, Phys. Sci. 2: 179. 1945
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. 2 n = 16.
Flowering spring. Open oak woods and grassland; 20-1000 m; Calif.
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.