Oreorchis angustata L. O. Williams ex N. Pearce & P. J. Cribb Edinburgh J. Bot. 54: 294. 1997.

西南山兰 xi nan shan lan

Plants 20-35 cm tall. Pseudobulbs pyriform-conic, 1-1.5 × 0.5-1 cm, several noded, sometimes persisting and forming a chain of pseudobulbs connected by a short rhizome. Leaf solitary, broadly lanceolate, plicate, ca. 19 × 2 cm, tapering at base into a petiole-like stalk ca. 6 cm, apex acute. Inflorescence 20-32 cm, with 2 tubular sheaths below middle; rachis 7-11 cm, laxly many flowered; floral bracts lanceolate, ca. 6 mm. Flower color not known; pedicel and ovary ca. 6 mm. Dorsal sepal lanceolate, ca. 5.5 × 1.2 mm, apex acute; lateral sepals lanceolate, slightly falcate, ca. 5 × 1.5 mm, apex subacute. Petals narrowly ovate-lanceolate, ca. 5 × 1.2 mm, apex subacute; lip oblong-ovate, ca. 4.5 × 2.2 mm, shortly clawed at base, 3-lobed near base; lateral lobes subovate, ca. 1.4 mm, apex obtuse-rounded; mid-lobe subobovate, ca. 3 × 2.2 mm, margin undulate, apex obtuse-rounded; disk with a pair of longitudinal lamellae at base and extending onto mid-lobe; lamellae ca. 2 mm. Column slightly arcuate, clavate, ca. 3 mm. Fl. Jun.

● Grassy slopes, open rocky places; ca. 3000 m. SW Sichuan, NW Yunnan.