Malaxis monophyllos (L.) Sw.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Scape 1–2.5 dm; lf solitary, clasping, oval to elliptic, 3–6 cm, usually at least half as wide; infl very slender, tapering to the tip; pedicels 1–2 mm; sep ovate to lance- ovate, 2–2.5 mm, the median erect, the lower deflexed beyond the lip; lateral pet oblanceolate, 1 mm, spreading horizontally; lip greenish-white, deflexed, 2–3 mm, broadly cordate, auriculate-lobed at base, tapering to a long point, minutely erose. Damp woods and bogs; circumboreal, in Amer. s. to N.J., Pa., Ill., Minn., Colo., and Calif. Most of the Amer. plants, including all ours, belong to var. brachypoda (A. Gray) F. J. A. Morris, with the fls merely resupinate, the lip lowermost. (M. brachypoda) Typical Eurasian var. monophyllos has the fls twisted a full circle at base, so that the lip is uppermost. (Microstylis m.)