Roots 3-8(-12)-branched at least 1 cm from stem attachment, (4-)10-30(-40) cm, fibrous, twisted, dry, thin threadlike segments apparent nearly entire length; buds minute. Stems 1(-3) per root, unbranched, elongation delayed 4-10 weeks after leaf initiation; base often narrowed, firmly attached to root; proximal internodes much shorter than those of midstem. Leaves basal and cauline, largest near base of stem, others often abruptly smaller on distal stem; basal petioles spreading, cauline petioles ascending; basal leaves more rounded and with fewer, wider lobes than cauline leaves. Inflorescences usually 4-8 flowers per 5 cm, ± open, cylindric to narrowly pyramidal, seldom less than 4 times longer than wide, spurs rarely intersecting rachis; pedicel spreading to ascending, usually less than 2 cm, rachis to midpedicel angle more than 30°; bracts markedly smaller, fewer lobed than leaves. Fruits erect. Seeds rectangular to crescent-shaped, 1.3-3.3 × 1.1-2.3 mm, not ringed on proximal end, ± wing-margined; seed coats usually lacking wavy ridges (present only in D. purpusii), cells brick-shaped (less than 3 times longer than wide), cell margins undulate or straight.

Distribution

North America, possibly others in Asia.

Discussion

Species 10+ (10 in the flora).

Selected References

None.

Key

1 Yellowish gland-based hairs present (at least apically) on pedicel; sepals reflexed. > 2
1 Yellowish gland-based hairs usually absent from pedicel; sepals spreading or reflexed. > 4
2 Sepals light blue to lavender. Delphinium lineapetalum
2 Sepals rose to pinkish or yellow > 3
3 Sepals magenta to rose. Delphinium purpusii
3 Sepals yellow. Delphinium xantholeucum
4 Cells of seed coat with undulate margins visible at 10×; mature fruits usually 3 or fewer times longer than wide. > 5
4 Cells of seed coat with smooth margins visible at 10× (roughened in D.parryi); mature fruits usually more than 3 times longer than wide. > 7
5 Sepals rarely reflexed; stems more than (50-)60 cm. Delphinium gypsophilum
5 Sepals (especially laterals) usually reflexed; stems less than 60(-100) cm. > 6
6 Lower petals white (contrasted with blue sepals). Delphinium recurvatum
6 Lower petals blue or white to pink (same color as sepals). Delphinium parishii
7 Sepals strongly reflexed. Delphinium lineapetalum
7 Sepals spreading or slightly reflexed, not strongly reflexed. > 8
8 Green leaves usually absent on proximal 1/5 of stem at anthesis; if present, then proximal portion of stem and/or petioles covered with short, arched hairs. > 9
8 Green leaves usually present on proximal 1/5 of stem at anthesis; proximal portion of stem and petioles glabrous to nearly glabrous (straight hairs). > 10
9 Lobes of proximal leaves less than 5 mm wide, or plants from less than 10km inland or less than 400m elevation. Delphinium parryi
9 Lobes of proximal leaves 5 mm or more wide, and plants from more than 10km inland and greater than 400m elevation. > 8
10 Leaves almost entirely on proximal 1/5 of stem at anthesis. Delphinium scaposum
10 Leaves primarily cauline at anthesis. > 11
11 Lobes of proximal leaves less than 4 mm wide; lateral sepals spreading to reflexed. Delphinium andersonii
11 Lobes of proximal leaves at least 4 mm wide; lateral sepals spreading. Delphinium umbraculorum