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.

Distribution

w North America.

Discussion

Species 6 (6 in the flora).

Selected References

None.

Lower Taxa

Delphinium antoninum, Delphinium basalticum, Delphinium bicolor, Delphinium glareosum, Delphinium luteum, Delphinium nudicaule

Key

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