Fl. Carol., 155. 1788.
Stems (20-) 40-90 (-150) cm; base reddish or not, ± pubescent. Leaves basal and cauline; basal leaves 0-10 at anthesis; cauline leaves 4-12 at anthesis; petiole 0.1-14 cm. Leaf-blade round to pentagonal, 1-8 × 2-12 cm, pubescence variable; ultimate lobes 3-29, width 2-10 mm (basal), 1-7 mm (cauline). Inflorescences (3-) 8-27 (-94) -flowered; pedicel (0.4-) 0.7-1.8 (-5.7) cm, nearly glabrous to glandular; bracteoles 1-3.5 (-6) mm from flowers, green or blue, linear, 2-7 mm, pubescence nearly glabrous to glandular. Flowers: sepals purple to blue to white, nearly glabrous, lateral sepals spreading, (7-) 9-14 (-17) × (3-) 3.5-6 (-8) mm, spurs ± upcurved, ascending 20-90° above vertical, (9-) 11-17 (-19) mm; lower petal blades ± covering stamens, 5-7 mm, cleft 2-4 mm; hairs centered, densest near base of cleft, white, sometimes blue or yellow. Fruits (10-) 12.5-18.5 (-27) mm, 4-4.5 times longer than wide, glabrous to puberulent. Seeds: seed-coat cells with surfaces pustulate or smooth.
Man., Ala., Ark., Colo., Fla., Ga., Ill., Iowa, Kans., Ky., La., Minn., Miss., Mo., N.C., N.Dak., Nebr., Okla., S.C., S.Dak., Tenn., Tex., Wis., Mexico
Subspecies 4 (4 in the flora).
|1||Basal leaves absent at anthesis, cauline leaves divided into many narrow (less than 2 mm wide) segments, blade not distinctly 3-parted; distalmost petiole less than 5 mm; sepals usually blue or purple (rarely white).||Delphinium carolinianum subsp. carolinianum|
|1||Basal leaves usually present at anthesis, and/or cauline leaf lobes usually wider than 2 mm, blade often distinctly 3-parted or more; distalmost petiole more than 5 mm; sepals blue or white.||> 2|
|2||Leaf blade distinctly 3-parted with few additional divisions; sepals blue to white; roots usually ± vertical, often without major branches.||Delphinium carolinianum subsp. vimineum|
|2||Leaf blade with 3–5 or more major divisions, each further divided into segments; sepals white to very pale blue; roots ±horizontal with several major branches.||> 3|
|3||Stems usually less than 45 cm; in thin soils over limestone in clearings of deciduous woods; leaf blade with 3 major divisions; e of Mississippi River.||Delphinium carolinianum subsp. calciphilum|
|3||Stems usually more than 45 cm; in deeper soils in grasslands; leaf blade with 5 or more major divisions; w of Mississippi River.||Delphinium carolinianum subsp. virescens|