Plants 1.5-3 dm; basal lvs 2 or 3, to 12 cm, 5-10(-15) mm wide; cauline sheaths 3-4, the lower with divergent recurved blade 2-5 cm; infl 2-6 cm, with glandular-puberulent axis, dense, the fls in 3 or 4 vertical ranks, individually widely spreading or somewhat deflexed, urceolate- cylindric, white or the lip creamy at the middle; sep and lateral pet 3.5-5 mm, the pet usually widest in the distal third and with one vein; lip 4-5 mm, ovate-oblong, rounded distally, often somewhat constricted near the middle, its basal callosities short, slender, less than 1 mm. Moist woods and bottomlands, and also in old fields and pastures; s. Pa. to sw. Mich. and Ill., s. to Fla. and Tex. Sept., Oct. Our plants, mainly autogamous and lacking a viscidium and rostellum (unique among our spp. in these regards) have been described as var. erostellata Catling, in contrast to var. ovalis, of Ark., La., and Tex., with slightly larger fls of normal structure.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.