落叶石豆兰 luo ye shi dou lan

Stelis hirta Smith in Rees, Cycl. 34: Stelis no. 11. 1816; Phyllorkis hirta (Smith) Kuntze; Tribrachia hirta (Smith) Lindley.

Rhizome creeping and rooting, 3-4 mm in diam. Pseudobulbs 5-10 mm apart from each other, ovoid-conic, 1.5-3 cm, ca. 1 cm in diam., with 2 leaves at apex. Leaves deciduous at anthesis; petiole ca. 5 mm; blade elliptic or oblong, ca. 12 × 2.5-3 cm, leathery, apex obtuse. Scape arising from base of leafless pseudobulb, to 15 cm; raceme pendulous, ca. 5 cm, with pubescent rachis, densely with many small flowers; peduncle ca. 3 mm in diam., with 2 or 3 tubular sheaths; floral bracts ovate, ca. 0.7 mm, apex acute, ciliate. Pedicel and ovary pubescent, ca. 1 mm. Flowers greenish white. Sepals free; dorsal sepal lanceolate, ca. 4.5 × 2 mm, abaxially densely pubescent, apex acute and slightly curved; lateral sepals slightly larger than dorsal sepal, obliquely ovate-lanceolate, abaxially densely pubescent, base adnate to column foot, apex acute. Petals oblanceolate, ca. 2 × 1.5 mm, membranous, margins fimbriate-ciliate; lip recurved, ± conduplicate, narrowly oblong, fleshy, ciliate, base attached to end of column foot by an immobile joint, apex retuse. Column ca. 1.5 mm; stelidia subulate, nearly as high as anther, ca. 0.5 mm; foot ca. 2.7 mm, with free part ca. 0.7 mm; anther cap papillate. Fl. Jul.

Tree trunks in evergreen broad-leaved forests; ca. 1800 m. S Yunnan [NE India, Myanmar, Nepal, Thailand, Vietnam].