Delphinium subsect. Bicoloria
Bot. Zhurn. (Moscow & Leningrad) 72: 687. 1987.
Roots 2-9-branched at least 1 cm from stem attachment, (5-)10-30(-40) cm, diffuse-fibrous, ± braided, dry; buds minute. Stems 1(-2) per root, usually unbranched, elongation delayed 2-6(-10) weeks after leaf initiation; base ± narrowed, ± tenuously attached to root; proximal internodes much shorter than those of midstem. Leaves basal and cauline, largest leaves near base of stem, others often abruptly smaller on distal portion of stem; basal petioles spreading, cauline petioles ascending; blade shape and lobing similar throughout. Inflorescences usually with 2-6 flowers per 5 cm, open, ± pyramidal, seldom more than 3 times longer than wide, spurs rarely intersecting rachis; pedicel spreading, usually more than 1.5 cm, rachis to midpedicel angle more than 30°; bracts markedly smaller and fewer lobed than leaves. Fruits spreading. Seeds obpyramidal, 1.6-2.9 × 0.7-1.9 mm, ± ringed at proximal end, usually wing-margined; seed coats lacking wavy ridges, cells elongate, cell margins straight.
w North America.
Species 6 (6 in the flora).
|1||Sepals red or yellow.||> 2|
|1||Sepals usually bluish, not red or yellow (sometimes maroon, white, or pink).||> 3|
|2||Sepals red to reddish orange, not waxy.||Delphinium nudicaule|
|2||Sepals bright yellow, appearing waxy.||Delphinium luteum|
|3||Sepals maroon; plants distinctly different from other individuals within populations.||> 4|
|3||Sepals blue or pink; plants usually similar to other individuals within populations.||> 6|
|4||Leaf segments more than 5, 5 mm or less wide.||> 4|
|4||Leaf segments 5 or fewer, more than 5 mm wide.||> 5|
|5||Proximal portion of stem hairy.||> 5|
|5||Proximal portion of stem glabrous.||> 3|
|6||Leaves mostly above proximal 1/3 of stem; flowers usually more than 15 per main inflorescence axis.||> 6|
|6||Leaves mostly on proximal 1/3 of stem; flowers usually fewer than 20 per main inflorescence axis.||> 7|
|7||Sepals pinkish; plants distinctly different from other individuals within populations.||> 8|
|7||Sepals dark blue to white; plants usually similar to other individuals within populations.||> 9|
|8||Plants in populations with red flowers.||> 8|
|8||Plants in populations with blue flowers.||> 7|
|9||Leaves ± succulent, clustered on proximal portion of stem.||> 10|
|9||Leaves not succulent, clustered on proximal portion of stem or not.||> 11|
|10||Lateral sepals dark blue to white, spreading to reflexed.||Delphinium antoninum|
|10||Lateral sepals dark blue, spreading.||Delphinium glareosum|
|11||Lower petal blade cleft usually less than 1/3 blade length.||Delphinium bicolor|
|11||Lower petal blade cleft more than 1/3 blade length.||Delphinium basalticum|