Subalpine larkspur, tall larkspur, Barbey's larkspur

Delphinium exaltatum Aiton var. (e) barbeyi Huth, Helios 10: 35. 1892; D. occidentale (S. Watson) S. Watson var. barbeyi (Huth) S. L. Welsh

Stems 50-150 cm; base green, glabrous. Leaves cauline, 8-24, absent from proximal 1/5 of stem at anthesis; petiole 1-14 cm. Leaf blade round to reniform, 4-8 × 7-15 cm, glabrous; ultimate lobes 5-9, width 8-50 mm. Inflorescences 10-50-flowered; pedicel 0.5-6 cm, glandular-puberulent; bracteoles 1-4(-8) mm from flowers, blue to green, awl-shaped, 5-14 mm, puberulent. Flowers: sepals dark bluish purple, sparsely puberulent, lateral sepals forward pointing, 13-23 × 5-8 mm, spurs ascending ca. 45° downcurved apically, 10-18 mm; lower petal blades ± covering stamens, 4-7 mm, clefts 2-3 mm; hairs centered, mostly near base of cleft, sparse elsewhere, white or yellow. Fruits 17-22 mm, 2.5-3 times longer than wide, puberulent. Seeds wing-margined; seed coat cells narrow but short, surfaces pustulate. 2 n = 16.

Flowering summer. Subalpine and alpine sites in wet soils; 2500-4100 m; Ariz., Colo., N.Mex., Utah, Wyo.

Delphinium barbeyi hybridizes extensively with D . glaucum in western Colorado and eastern Utah, where plants appearing to be hybrid [ D . × occidentale (S. Watson) S. Watson] are often far more common than plants of either putative parent. Several other names have been used for these plants, including D . elatum var. occidentale S. Watson, D . abietorum Tidestrom, and D . scopulorum subsp. occidentale (S. Watson) Abrams. Delphinium barbeyi is also known to hybridize with D . ramosum and D . sapellonis .