Heart-leaved twayblade

Ophrys cordata Linnaeus, Sp. Pl. 2: 946. 1753; Bifolium cordatum (Linnaeus) Nieuwland; Diphryllum cordatum (Linnaeus) Kuntze; Distomaea cordata (Linnaeus) Spenner; Neottia cordata (Linnaeus) Richard; Pollinirhiza cordata (Linnaeus) Dulac

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.

Varieties 2 (2 in the flora): n North America, Europe, Asia (Japan), Iceland.

Listera cordata is the most widespread species in the genus.

SELECTED REFERENCE

Ackerman, J. D. and M. R. Mesler. 1979. Pollination biology of Listera cordata (Orchidaceae). Amer. J. Bot. 66: 820–824.