Stems (40-)80-130(-180) cm; base usually green, glabrous. Leaves mostly on proximal 1/3 of stem, usually absent from proximal 1/5 stem at anthesis; basal leaves 0-4 at anthesis; cauline leaves 10-20 at anthesis; petiole 0.5-15 cm. Leaf blade round on proximal stem, ± cuneate on distal stem, 1.5-9 × 2-14 cm, glabrous; ultimate lobes 3-15, width 15-30 mm (basal), 1-20 mm (cauline). Inflorescences 25-50-flowered, ± dense; pedicel 0.5-2 cm, glandular-puberulent; bracteoles 4-5 mm from flowers, green to blue, lanceolate-linear, 3-7 mm, glandular-puberulent. Flowers: sepals dark blue, puberulent, lateral sepals forward pointing to spreading, 12-15 × 5-7 mm, spurs straight, within 20° of horizontal, 12-16 mm; lower petal blades slightly elevated, exposing stamens, 6-8 mm, clefts 2-3 mm; hairs centered, mostly near base of cleft, white. Fruits 10-15 mm, 3-4 times longer than wide, glandular-puberulent. Seeds narrowly wing-margined; seed coat cells with surfaces somewhat roughened. 2 n = 16. Flowering late spring-summer. Rocky streambeds; 1500-1800 m; Wash. Delphinium multiplex hybridizes with D . glaucum and D . distichum .