注：名称已修订，正名是：细距舌唇兰 Platanthera bifolia
Platanthera bifolia (Linnaeus) Richard, De Orchid. Eur. 35. 1817.细距舌唇兰 xi ju she chun lan
Orchis bifolia Linnaeus, Sp. Pl. 2: 939. 1753; Habenaria bifolia (Linnaeus) R. Brown; Platanthera metabifolia F. Maekawa.
Plants 28-42 cm tall. Rootstock tuberous, ovoid-fusiform, tapering at base, 2.5-3 × 0.8-1.4 cm. Stem erect, with 1 or 2 tubular sheaths at base, 2-leaved. Leaves basal, subopposite, spatulate-elliptic, oblong, or elliptic, 9-12 × 1.8-3.5 cm, gradually contracted at base, apex obtuse. Peduncle slender to robust, with 2-4 scattered, lanceolate bracts; rachis 9-19 cm, laxly to subdensely 7-17-flowered; floral bracts lanceolate, 15-20 mm, basal ones exceeding ovary. Flowers fragrant, white, greenish white, or green; pedicel and ovary arcuate, cylindric, 14-15 mm. Dorsal sepal erect and forming a hood with petals, ovate to broadly ovate, cymbiform, 5.5-6 × 4-4.5 mm, glabrous, apex obtuse; lateral sepals spreading, ovate-lanceolate, oblique, 6-7 × 3.5-4 mm, glabrous, apex subacute. Petals linear-lanceolate, oblique, 5.5-6 × ca. 1 mm, apex acute; lip spreading, ligulate, 9-10 × 1-1.5 mm, thickened, entire, apex obtuse; spur pendulous, cylindric, slender, 20-25 × 1.5-1.8 mm, apex subacute. Column stout; staminodes conspicuous; anther locules slightly divergent; pollinia ellipsoid, with long caudicles and suborbicular viscidia; rostellum belt-shaped; stigma lobes confluent, concave, lying directly below rostellum. Fl. Jul-Aug, fr. Aug-Sep. 2n = 42.
Forests on slopes, damp meadows; 200-2800 m. Gansu, Hebei, Heilongjiang, Henan, Jilin, Liaoning, Qinghai, Shandong, Shanxi, Sichuan [Japan, Korea, Mongolia, Russia; N Africa, W Asia, Europe].
The Chinese plants do not differ significantly from the widespread Eurasian Platanthera bifolia. Its sister and equally widespread species, P. chlorantha, is also found in China. The distinctness of P. metabifolia, originally described from Japan, is questionable once the full range of variation in P. bifolia is considered.
The extensive extra-Chinese synonymy is not cited here.