Liparis siamensis Rolfe ex Downie Bull. Misc. Inform. Kew. 1925: 371. 1925.

滇南羊耳蒜 dian nan yang er suan

Herbs, terrestrial. Pseudobulbs ovoid, 1-2 cm × 8-15 mm, noded, ± enclosed by white membranous sheaths. Leaves 2; petiole sheathlike, 2-6 cm, amplexicaul, not articulate; blade ovate-elliptic or elliptic, 6.5-15.5 × 3-6.5 cm, membranous or herbaceous, base contracted into petiole, margin entire, apex acute or shortly acuminate. Inflorescence 10-20 cm; rachis several to more than 10-flowered; floral bracts ± reflexed, lanceolate, 4-7 mm. Flowers green; pedicel and ovary 1.1-1.5 cm. Dorsal sepal narrowly oblong, 7.5-8.5 × ca. 1.8 mm, 3-veined, apex obtuse; lateral sepals oblong-ovate, 6-7 × ca. 3 mm, slightly oblique, 5-veined, apex obtuse. Petals narrowly linear, 7-8 × ca. 0.7 mm, widened toward apex, 1-veined; lip broadly obovate to transversely oblong, 5-5.5 × ca. 7 mm, margin irregularly denticulate, apex emarginate, base narrowed into a short claw, with a basal callus; callus ca. 1 mm high, apex 2-lobed. Column arcuate, 3-3.5 mm, with narrow wings on both sides. Fl. Aug. 2n = 42.

Forests; ca. 700 m. S Yunnan [Laos, Myanmar, Thailand].