Montana Field Guide

This larkspur is a perennial with 1 to several erect, sometimes hollow stems, 15-50 cm tall, from a thick, branching root. The leaves are mostly confined to the lower 1/3 of the stem, the lowest ones withering by flowering time; the leaf blades are usually somewhat fleshy, 2-5 cm broad, and three times dissected into linear or oblong segments; the petioles of the lower leaves are 1-5 times as long as the blades; foliage is glabrous. The open inflorescence has one main stem with 3-15 flowers and usually 1 to several smaller side branches; the spreading sepals are 11-15 mm long and generally deep blue; the uppermost sepal has a long tubular portion (spur) projecting backwards; the lower petals are also deep blue and have a deep notch, 1/4-1/2 the length of the blade; the erect upper petals are whitish with blue tips; the stalk of each flower is 2-4 times the length of the calyx spur. The three-parted seed capsule is usually glabrous.

Delphinium is a difficult genus and a technical key should be consulted. Roots are necessary for positive identification.

Sagebrush valleys and hills, into open forests; sparsely vegetated, sandy, probably calcareous soils.

POLLINATORS
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans, Bombus appositus, Bombus auricomus, Bombus borealis, Bombus centralis, Bombus fervidus, Bombus flavifrons, Bombus mixtus, Bombus occidentalis, Bombus pensylvanicus, Bombus griseocollis, Bombus impatiens, and Bombus kirbiellus (Plath 1934, Macior 1974, Bauer 1983, Thorp et al. 1983, Wilson et al. 2010, Colla and Dumesh 2010, Koch et al. 2012, Pyke et al. 2012, Miller-Struttmann and Galen 2014, Williams et al. 2014).