Crepidium concavum (Seidenfaden) Szlachetko Fragm. Florist. Geobot., suppl. 3: 125. 1995.

凹唇沼兰 ao chun zhao lan

Malaxis concava Seidenfaden, Bot. Tidsskr. 65: 325. 1970.

Plants terrestrial. Pseudobulbs small, enclosed in sheaths. Leaves 2, elliptic-oblong or narrowly elliptic, 7-11 × 1.5-2 cm, base contracted into a sheathlike petiole 1-1.5 cm, apex acuminate. Inflorescence erect; rachis ca. 2 cm, ca. 10-flowered; floral bracts narrowly lanceolate, very small. Flowers 3-4 mm in diam.; pedicel and ovary 3-4 mm. Dorsal sepal oblong, 2-3 × ca. 0.8 mm; lateral sepals rather broad and short, obtuse. Petals narrowly linear, 2-3 × ca. 0.3 mm; lip superior, oblong-ovate or nearly broadly oblong in outline, 2-3 × 1.5-2.5 mm, adaxially with 2 thick short lamellae, base with 2 short auricles decurrent backward ± embracing column, apex emarginate; auricles 0.4-0.6 mm. Column 2-2.5 mm, stout, upper part winged. Fl. Jun.

Humid places in forests; ca. 1200 m. S Yunnan [Thailand].