Monographs Details: Listera convallaroides (Sw.) Elliott
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - Stem 1–3 dm; lvs broadly ovate, 3–5(–7) cm, longer than the peduncle, obtuse or subacute; axis, pedicels, and ovary glandular-puberulent; bracts 3– 5 mm; fls up to ca 20; sep and lateral pet 4–5 mm, reflexed; lip greenish, translucent, cuneate, 9–10 mm, deeply retuse and ca 5 mm wide at the summit, usually with a short (often obscure) tooth on each side near the narrow base; column 2.5–4 mm; 2n=36. Wet woods, usually in deep shade; Nf. to Alas., s. to Mass., N.Y., Mich., Minn., and Ariz. July, Aug. (Ophrys c.) A hybrid with no. 1 [Listera auriculata Wiegand] is L. ×veltmanii Case.

Common Names:broad-leaved twayblade