Delphinium caeruleum Jacquem. ex Cambess.

Flowering from July to September.

Delphinium caeruleum var. caeruleum is close relative of Delphinium caeruleum var. majus, but differs from the latter in its proximal leaves present at anthesis (vs. absent), cauline leaf blade to 8 cm wide (vs. 12 cm), ultimate lobules 2-3 mm wide (vs. 2.5-5 mm).

Delphinium caeruleum is occurring in Gansu, Qinghai, W Sichuan, NW Yunnan, Xizang of China, Bhutan, Nepal.

Stem 8-60 cm tall, appressed puberulent, without glandular hairs, usually branched. cauline leaf blade to 8 cm wide, apically acute, adaxially densely puberulent or velutinous, base cordate; primary lobes separate for at least 90% of blade radius; central lobe rhombic or obovate-rhombic, 1-3 × dissected, distally 1-2-lobulat, apex acute; ultimate lobules linear, 2-3 mm wide; Proximal leaves present at anthesis; Corymb 5-14 cm, 1-7-flowered, finely puberulent; proximal bracts leaflike or 3-sect, distal ones linear. Pedicels 3.5-8 cm; bracteoles borne near middle of pedicel or distally, lanceolate-linear, 4-10 mm. Sepals purple-blue, rarely white, abaxially puberulent; spur subulate, 1.5-2.8 cm, nearly straight or slightly recurved, base 2-4 mm in diameter; other sepals 1.2-2.1 cm. Petals undivided, glabrous. Staminode limb broadly obovate or suborbicular, entire or emarginate, yellow barbate. Filaments glabrous or pilose. Carpels 4 or 5; ovaries puberulent; Spur 1.8-2.8 cm, base 2-3 mm in diameter.

The chromosomal number of Delphinium caeruleum is 2n = 16 (Yang, 1996).

Growing in grassy or gravelly slopes; 2100-4000 m.