22. Dendrobium devonianum Paxton, Paxton’s Mag. Bot. 7: 169. 1840.
齿瓣石斛 chi ban shi hu
Callista devoniana (Paxton) Kuntze; C. moulmeinensis (E. C. Parish ex J. D. Hooker) Kuntze; Dendrobium devonianum var. rhodoneurum H. G. Reichenbach; D. moulmeinense E. C. Parish ex J. D. Hooker; D. pulchellum Roxburgh ex Lindley var. devonianum (Paxton) H. G. Reichenbach.
Stems pendulous, cylindric, 50-70(-100) cm, slender, 3-5 mm in diam., slightly fleshy, unbranched, with many nodes, internodes 2.5-4 cm, often pale brown tinged with dirty black when dry. Leaves narrowly ovate-lanceolate, 8-13 × 1.2-2.5 cm, leathery, base with clasping sheath, apex long acuminate; leaf sheath often with purplish red dots, papery when dry. Inflorescences often several, on old leafless stems, 1- or 2-flowered; peduncle green, ca. 4 mm; basal sheaths 2 or 3, dry, membranous; floral bracts ovate, ca. 4 mm, membranous, apex subacute. Pedicel and ovary green, tinged with brown, 2-2.5 cm. Flowers scented, spreading, thinly textured; dorsal sepal white, upper part tinged with purplish red, veins purple, lip white, front purplish red, with purplish red stripes on both sides below middle, disk with a yellow spot on either side, column white, both front sides with purple stripes, anther cap white. Dorsal sepal ovate-lanceolate, ca. 25 × 9 mm, 5-veined, apex acute; lateral sepals similar in size and shape, but base slightly oblique; mentum subglobose, ca. 4 mm. Petals ovate, ca. 26 × 13 mm, 3-veined, lateral main veins often branched, base shortly clawed, margin shortly fimbriate, apex subacute; lip suborbicular, ca. 3 cm, base shortly clawed, margin compound fimbriate, adaxially densely barbellate. Column ca. 3 mm; anther cap subconic, densely finely papillate, front margin irregularly dentate, apex slightly concave.
Epiphytic on tree trunks in thick mountain forests; ca. 1900 m. NW Guangxi (Longlin), SW Guizhou (Luodian, Xingyi), SE Xizang (Mêdog), SE to W Yunnan [Bhutan, NE India, Myanmar, N Thailand, Vietnam].