Puberulent to subglabrous; stems 1 or 2 on a carrot-like or tuberous vertical root, 3-10 dm; lvs rather numerous, alternate or scattered or some opposite or subverticillate, linear, 6-15 cm, to 5(-8) mm wide; umbels subsessile in the upper axils, 10-25-fld; cor pale greenish to yellow, its lobes reflexed, 4.5-5.5 mm; hoods pale, 3-4 mm, ca equaling the gynostegium; horn adnate to the hood for most of its length (forming a ventral ridge), only the short tip free between the short terminal lobes of the hood; frs slender, erect, 9-12 cm. Dry prairies and glades; se. Minn.; Great Plains, from se. Mont. to n. Tex., e. to se. S.D., s. Mo., and w. Ark. June-Aug. (Acerates s.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
