直葶石豆兰 zhi ting shi dou lan

Rhizome creeping, ca. 1.5 mm in diam. Pseudobulbs ca. 1 cm apart on rhizome, ovoid, ca. 8 mm, ca. 5 mm in diam., with 2 leaves at apex. Leaves deciduous at anthesis, not seen. Scape from base of leafless pseudobulb, erect, ca. 8 cm; peduncle slender, with 2 or 3 sheaths ca. 4 mm; raceme sparsely with several secund flowers; rachis glabrous; floral bracts ovate, 1.5-2 mm, apex acute. Pedicel and ovary ca. 4 mm. Flowers thinly textured, pale yellow. Dorsal sepal ovate, ca. 4 × 2.2 mm, entire, acute; lateral sepals ovate-lanceolate, ca. 6 × 2 mm, base adnate to column foot, margin entire, apex acute. Petals ovate-lanceolate, ca. 2.8 × 1.2 mm, base ca. 1/2 width adnate to column foot, apical margin ± denticulate, apex obtuse; lip recurved, narrowly oblong, ca. 3.5 × 0.7 mm, fleshy, centrally channeled at base, adaxially densely finely papillate, apex obtuse. Column ca. 1.5 mm; foot ca. 1.5 mm, with free part ca. 0.5 mm; stelidia dentate, apex subulate; anther cap subglobose, finely papillate. Fl. Mar.

Tree trunks in evergreen broad-leaved forests; ca. 900 m. S Yunnan [Myanmar, N Thailand].