Leaves: basal leaves usually present at anthesis; basal and proximal cauline leaves rarely cleft more than 4/5 radius of blade. Leaf blade: ultimate lobes 3-5, width more than 15 mm. Inflorescences: pedicel usually glabrous. Flowers: lateral sepals 11-17 mm, spur 10-18 mm; lower petal blades 5-8 mm; hairs symmetrically distributed. 2 n = 16. Flowering spring. Wooded ravines, near streams; 300-1300 m; Calif. Although Delphinium patens has not been reported outside California, subspp. hepaticoideum and/or montanum may grow in mountains of northern Baja California, Mexico. Although it hybridizes with Delphinium parryi and D . umbraculorum , D . patens subsp. hepaticoideum usually flowers early enough not to overlap in any given site with flowering time of those species.

Likely to be confused only with Delphinium umbraculorum , D . patens subsp. hepaticoideum may be distinguished from that species by its ringed, unwinged seeds, recurved fruits, and lack of arched hairs. Contrasting features of D . umbraculorum are presence of unringed, winged seeds, erect fruits, and arched hairs.