The habit of Spiranthes vernalis is variable: inflorescences range from secund to loosely and even densely coiled, and flower shapes vary as well. The most consistent diagnostic character is the presence in inflorescences of copious articulate, pointed trichomes that readily distinguish S. vernalis from similar species.
Plants 2-8 dm; basal lvs narrow, 5-25 cm נ4-12 mm; cauline sheaths usually 5-7, the lower with blades to 15 cm; infl 3-15+ cm, its axis densely beset with pointed hairs 0.2-0.3 mm, the fls mostly in a single long spiral (seldom more condensed), spreading or somewhat deflexed, urceolate-cylindric, white or ivory with the lip more yellowish centrally; sep and lateral pet 5-9.5 mm, the upper sep a bit longer than the spreading-divergent lateral ones; lip 5-8 mm, ovate or broadly ovate, basally cuneate, distally ±obtuse and crisped-erose, papillate on both sides especially distally, its basal callosities 0.5-1 mm, higher than thick; 2n=30. Open, sandy, moist or dry acid soil; Mass. to Fla., w. to O., se. S.D., Kans., and Tex.; Mex. and C. Amer. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
