Platanthera mandarinorum var. formosana (T. P. Lin & K. Inoue) S. S. Ying
Plants 10-25 cm tall. Tuberoids ovoid to fusiform, 2-4 cm long, 4-7 mm thick, producing new shoot from base. Stem short, distinctly ridged, with one or two larger basal leaves and few bract-like smaller leaves toward inflorescence. Basal leaves nearly perpendicular to stem, sessile, ovate, oblong to lanceolate, 3-6 cm long, 1.2-3 cm wide, acute to acuminate at apex, truncate and embracing stem at base. Inflorescence 3-10 cm long, 3-10-flowered; bracts lanceolate, 10-15 mm long, 3-5 mm wide, acute or acuminate, lower ones larger; pedicel and ovary 10-16 mm long. Flowers greenish; dorsal sepal deltoid, 5-7 mm long, 4-4.5 mm wide, apex obtuse, 3-nerved; lateral sepals reflexed, obliquely linear-lanceolate, 7-9 mm long, 1.3-2 mm wide, acute or obtuse at apex; petals spreading, not forming hood with dorsal sepal, obliquely ovate-lanceolate, 6-8 mm long, 3.5 mm wide, acute or obtuse; lip fleshy, descending, linear-lanceolate, 8-10 mm long, 2-2.5 mm wide, apex obtuse, slightly dilated into square base, spur cylindrical, slightly curved, 12-18 mm long, obtuse or sharp at tip; column 3-4 mm tall; anther cells clavate, 2.5 mm long, widely separated and somewhat divergent at bases, staminodes elongate ellipsoid, 1.5 mm long; pollinia ovoid-ellipsoid, 1.5 mm long, caudicle ca. 1.5 mm long, viscidium orbicular discoid; stigma concave, transversely broad; rostellum narrow tape-like, slightly curved, situated between connective and stigma.
TAIPEI: Peichiatienshan, Lin 145. ILAN: Chilanshan, Lin 223; Logging road no. 170, Su & Chen 8295. PINGTUNG: Peitawushan, Su 9358.
Endemic, moist grasslands and forest edges, also in moss on wet rocks, 1,600-2,700 m.