Delphinium nuttallianum Pritzel var. pilosum C. L. Hitchcock

Flowers: sepals dark blue to purple, lateral sepals 16-21 × 6-11 mm, spurs 13-18 mm; lower petal blades with cleft less than 2 mm; hairs usually white.

Flowering late spring-early summer. Dry meadow edges, sage scrub, open woodlands and edges; not on soils derived from limestone; 600-3100 m; Alta., B.C., Sask.; Idaho, Mont., Nebr., N.Dak., S.Dak., Wyo.

Rydberg's Delphinium bicolor var. montanense tends to have more pubescence and larger flowers but is otherwise typical and apparently fully intergrades with D . bicolor subsp. bicolor . Often referred to as one of the low larkspurs in poisonous-plant literature, the plant is abundant on some ranges and is the cause of some livestock poisonings.