Spiranthes tuberosa Raf.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Orchidaceae

• Scientific Name

  Spiranthes tuberosa Raf.

• Description

  Species Description - Slender, 1.5–3 dm; root single (unique among our spp.), turbinate, to 6(–10) cm, 4–12 mm thick, sometimes accompanied by the partly decomposed root of the previous year; basal lvs ephemeral, usually ovate, short-petiolate, 2–4(–5) cm, 6–15(–20) mm wide; usually 4–6 bladeless sheaths on the stem; infl 2–8+ cm, its rachis (as well as the whole herbage) glabrous, the ± cylindric fls rather closely set in a single long spiral, 3–5.5 mm, pure white, the lip broadly ovate, distally truncate or sometimes rounded and crisped or slightly erose, puberulent with minute hairs 0.2–0.4 mm on the upper surface, minutely papillate below, the basal callosities less than 1 mm. Acid, usually rather dry soil; Mass. to Fla., w. to Ill., Mo., and Tex. Aug., Sept. (S. grayi; S. beckii, misapplied)

• Common Names

  little ladies'-tresses