Plants 8-29 cm. Stems purplish green, succulent, glabrous. Leaves: blade dark green, ovate, ovate-oblong, or elliptic, 1.3-4 × 0.5-2.1 cm, base often subcordate, apex obtuse to apiculate. Inflorescences 5-25-flowered, lax, 45-110 mm; floral bracts suborbiculate-ovate, 2 × 1 mm, apex obtuse; peduncle and rachis slightly glandular-puberulent; bracts, pedicel, and ovary glabrous. Flowers reddish purple; pedicel filiform, 4-6 mm; dorsal sepal ovate-elliptic, concave, 1.5 × 1 mm, apex obtuse; lateral sepals ovate, falcate, 1.5 × 1 mm, apex obtuse; petals recurved, oblong, 1.5 × 0.5 mm, apex obtuse; lip linear, 6-12 × 1.5-2 mm, base extended into 2 rounded, linear lobes, projecting distally, partially surrounding column, distal half split into 2 linear-lanceolate lobes with minute tooth in sinus; column 0.5-1 × 0.5-1 mm. Capsules horizontal, ovoid, 8 × 5 mm, with relatively few large seeds. Flowering Jan (Fla.)--Jul. Rich humus of low moist woods, marshes, sphagnum bogs, usually in association with rhizomes of cinnamon fern (Osmunda cinnamomea) and royal fern (O. regalis); 0--1000 m; N.B., N.S., Ont., Que.; Ala., Ark., Fla., Ga., La., Miss., N.J., N.Y., N.C., Okla., Pa., S.C., Tenn., Tex., Vt. Perianth parts of Listera australis persist as capsules mature. This is such a small orchid that it can easily be overlooked; it may have a wider distribution than recorded here.
Stem 1.5-3 dm; lvs ovate, 1-3.5 cm, shorter than the peduncle, rounded at base, abruptly apiculate; axis and pedicels glandular; ovaries glabrous; bracts 1 mm; fls up to ca 25, greenish-purple to dull red, the sep and lateral pet ovate-oblong, reflexed, 2 mm; lip 6-10 mm, narrowly oblong, cleft half its length into 2 slender lobes, and with a pair of narrow, retrorse auricles at the base; column under 1 mm. Shaded bogs and wet woods, mainly on the coastal plain from N.J. to Fla. and e. Tex.; irregularly in Ky., Tenn., N.Y., Vt., e. Ont., s. Que., N.B. and N.S. June, July. (Ophrys a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.