Stems 1.5-3 dm, villous; lvs linear-oblong to more often lanceolate, 4-7 cm, obtuse, sparsely villous on both sides; umbel solitary, erect, terminal, short-peduncled; pedicels hirsutulous; cor pale greenish-yellow or somewhat purplish, its lobes 4-5 mm; hoods 2.5-3.5 mm, erect, appressed to the gynostegium, the base adjacent to the cor, the obtuse summit reaching distinctly beyond the projecting angle of the anther-wings or nearly to the top of the gynostegium; horns none. Dry upland woods and prairies; not common; Wis. and n. Ill. to Io., Kans., and N.D. (A. nuttalliana; Acerates l.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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