圆叶石豆兰 yuan ye shi dou lan

Bulbophyllum aureolabellum T. P. Lin; B. gracillimum Hayata (1912), not Rolfe (1907); B. somae Hayata.

Rhizome creeping, slender, 0.5-1 mm in diam., noded, with internodes 1-2 cm, each node bearing 1 leaf and 1-3 roots. Pseudobulb absent. Leaf subsessile; blade subelliptic or orbicular, 5-30 × 5-10 mm, fleshy-thickened, apex obtuse. Scape arising from base of petiole, erect, 7-40 mm; peduncle slender, ca. 0.3 mm in diam., with 2 or 3 sheaths, terminating in a solitary flower; floral bracts ovate, 1.3-3 mm, membranous, apex acute. Pedicel and ovary 2-5 mm. Flowers pale yellow, with purplish brown stripes on sepals and petals and usually heavily tinged with purplish brown on lip. Sepals free, similar, ovate-lanceolate, 6-16 × 2-4 mm, apex long acuminate; lateral sepals slightly larger. Petals oblong, subelliptic, or linear, 1.5-4 × 1-2 mm, entire, obtuse; lip recurved, ovate-elliptic, 1.5-5 × 0.3-3 mm, 3-veined, base attached to end of column foot by an immobile joint, basal margins ± undulate, apex obtuse. Column 1-2 mm, stout; foot purplish brown, 1.3-4 mm, with free part 0.8-1.8 mm; stelidia deltoid, inconspicuous; anther cap glabrous. Fl. May. 2n = 40.

Tree trunks in forests; 300-2400 m. N Guangdong, E Guangxi, Taiwan, SE and SW Yunnan [Japan, Korea].