Plants 5-33 cm. Stems green to reddish purple, succulent, glabrous. Leaves: blade broadly to narrowly ovate-cordate or deltate, 0.9-2(-4) × 0.7-2(-3.8) cm, apex mucronate. Inflorescences 5-25-flowered, lax to dense, 20-100 mm, slender; floral bracts ovate, 1-1.5 × 1 mm; peduncle and rachis slightly glandular-puberulent or glabrate; bracts, pedicel, and ovary glabrous. Flowers yellow-green, green, or reddish purple; pedicel slender, 2-3 mm; dorsal sepal ovate-oblong to oblong-elliptic, 2-3 × 1 mm, apex obtuse; lateral sepals ovate-oblong to oblong-elliptic, slightly falcate, 2-3 × 0.5-1.5 mm, apex obtuse; petals elliptic to oblong-linear, 1.5-2.5 × 0.5-1 mm, apex obtuse; lip linear-oblong, cleft 1/2 -2/3 its length into 2 linear-lanceolate lobes, 3-4 × 1-1.5 mm; disc with pair of spreading, linear lobes, apices acute; column 0.5 × 0.5 mm. Capsules semierect, subglobose, 5 × 4 mm. Listera cordata is the most widespread species in the genus.
Stems 1-2.5 dm; lvs 1-3 cm, shorter than the peduncle, truncate or subcordate at base, but also abruptly contracted at the point of insertion; axis, pedicels, and ovary glabrous; bracts minute, 1 mm; fls up to ca 25, green to purple or red; sep and lateral pet 2-2.5 mm, ovate oblong; lip 3-5 mm, with 2 projecting lateral teeth near the base, cleft to the middle or below into divergent linear lobes; column 0.5 mm. Deep wet woods and sphagnum-bogs; circumboreal, s. in Amer. to N.Y., Pa., Mich., and Minn., and in the mts. to N.C. and N.M. June, July. (Ophrys c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.