西畴石斛 xi chou shi hu

Stems clustered, cylindric, equally thick above and below, upper part ± upcurved, 10-13 cm, ca. 4 mm in diam., unbranched, with many nodes, internodes 1-2 cm, enclosed in leaf sheaths that turn grayish white when mature. Leaves oblong or oblong-lanceolate, to 4 × ca. 1 cm, leathery, base with clasping sheath, apex obtuse and unequally bilobed. Inflorescence arising laterally on previous year’s leafless stem, ca. 2 cm, 1- or 2-flowered; floral bracts small. Pedicel and ovary yellowish green, ca. 6 mm. Flowers fragrant, not spreading; sepals and petals white, slightly tinged with pink, mentum pale yellowish green, lip white, disk yellow. Dorsal sepal suboblong, ca. 12 × 4 mm, apex acute; lateral sepals similar in size; mentum narrowly tubular, ca. 10 mm. Petals obovate-rhombic, slightly shorter than dorsal sepal, ca. 4 mm wide; lip subovate, ca. 16 mm, ca. 9 mm wide at most, base clawed, apex obtuse, lateral margins upcurved below middle, margin fimbriate; disk densely curled pale yellow villous.

● Epiphytic on tree trunks in mountain forests on limestone; ca. 1900 m. SE Yunnan (Xichou).

The present authors have not seen the type specimen (at IBSC). This treatment is based on the protologue.