Roots usually with elongate single central axis, axis ± vertical, terminal branches (if present) sometimes approaching horizontal. Stems 20-60(-100) cm. Leaves usually basal and cauline at anthesis; distalmost petioles more than 5 mm. Leaf blade distinctly 3-parted; ultimate lobes of midcauline leaf blades 3-9, width 3-10 mm. Flowers: sepals various shades of blue to white. 2 n = 16, 32. Flowering late winter-early summer. Sandy or clay soils, coastal prairies, pine woods, Prosopis or Quercus scrub; 0-300 m; Ark., La., Okla., Tex.; Mexico (Coahuila, Nuevo León, and Tamaulipas). Delphinium carolinianum subsp. vimineum hybridizes with D . madrense especially on southern edge of Edwards Plateau in Texas.