Roots 4-15-branched, 10-80 cm, twisted fibrous, dry; buds more than 3 mm, usually present throughout dormant season. Stems (1-)3-8(-19) per root, usually unbranched, elongation commencing within 2 weeks of leaf initiation; base not narrowed, firmly attached to root; proximal internodes similar in length to those of midstem. Leaves cauline, largest at or slightly below middle of stem, others gradually reduced into bracts; petiole ± ascending; blade shape and lobing similar throughout. Inflorescences usually 5-10 flowers per 5 cm, ± dense, cylindric (greatly shortened in some), spurs rarely intersecting rachis; pedicel ± spreading, usually less than 2 cm; rachis to midpedicel angle more than 30°; bracts ± similar to leaves but smaller. Fruits erect. Seeds rectangular to crescent-shaped, 1.5-3.5 × 1.2-2.5 mm, not ringed at proximal end, wing-margined or not; seed coats ± with small irregular wavy ridges or ripples, cells elongate, cell margins straight.

Distribution

North America, Mexico, at least 1 species and probably more in Asia.

Discussion

Species 13 or more (12 in the flora).

Members of Delphinium subsect. Exaltata are the typical tall larkspurs of poisonous-plant literature. Their abundance on some ranges, combined with their large size and toxicity, make them significant sources of livestock poisoning. Several of the species in this subsection (Delphinium andesicola, D. californicum, D. glaucum, D. novomexicanum, D. robustum, D. sapellonis, and the Mexican D. valens Standley) form a tightly knit group in which the degree of difference between members of the group and patterns of variation within the members appear largely determined by the degree and length of isolation in the various mountain ranges where the plants are found. Delphinium andesicola, D. novomexicanum, D. robustum, D. sapellonis, and D. valens form the southern Cordilleran complex.

Selected References

None.

Lower Taxa

Delphinium alpestre, Delphinium andesicola, Delphinium barbeyi, Delphinium brachycentrum, Delphinium californicum, Delphinium exaltatum, Delphinium glaucescens, Delphinium glaucum, Delphinium novomexicanum, Delphinium ramosum, Delphinium robustum, Delphinium sapellonis

Key

1	Leaves present on proximal 1/5 of stem at anthesis.	> 2
1	Leaves absent from proximal 1/5 of stem at anthesis.	> 4
2	Lateral sepals acute at apex; Alaska, Yukon.	Delphinium brachycentrum
2	Lateral sepals rounded at apex; Colorado, New Mexico.	> 3
3	Stems less than 30 cm.	Delphinium alpestre
3	Stems more than (45–)70 cm.	Delphinium ramosum
4	Sepals in bud brownish, yellowish, or purple.	> 5
4	Sepals in bud blue or purple, rarely white or pink, not brownish or yellowish.	> 6
5	Sepals (in bud) yellowish or brownish purple, becoming progressively browner or yellower with age.	Delphinium sapellonis
5	Sepals (in bud) purple to lavender, at least some fading brownish with age.	Delphinium novomexicanum
6	Hairs in inflorescence gland-based.	> 7
6	Hairs in inflorescence (if present) not gland-based.	> 8
7	Inflorescence more than 3 times longer than wide.	Delphinium barbeyi
7	Inflorescence less than 3 times longer than wide.	Delphinium barbeyi
8	Lobes of midcauline leaves less than 3 times longer than wide.	> 9
8	Lobes of midcauline leaves more than 3 times longer than wide (neither e of Great Plains nor along coastal California).	> 10
9	Sepals whitish to pale lavender or purple; e of Great Plains.	Delphinium exaltatum
9	Sepals lavender to greenish white; coastal California.	Delphinium californicum
10	Stems finely, evenly puberulent throughout.	Delphinium ramosum
10	Stems glabrous, or if pubescent, then only in inflorescences.	> 11
11	Leaf blades laciniate, lobe tips gradually tapered to mucronate apex.	> 12
11	Leaf blades seldom laciniate, lobe tips abruptly tapered to mucronate apex.	> 13
12	Spurs blunt tipped, purple.	Delphinium andesicola
12	Spurs pointed, dark blue.	Delphinium robustum
13	Rarely more than 25 flowers per plant; sepals dark blue.	Delphinium glaucescens
13	Rarely fewer than 25 flowers per plant; sepals bluish purple to lavender.	Delphinium glaucum