竹枝石斛 zhu zhi shi hu

Grastidium salaccense Blume, Bijdr. 333. 1825; Callista intermedia (Teijsmann & Binnendijk) Kuntze; C. salaccense (Blume) Kuntze; Dendrobium bambusifolium E. C. Parish & H. G. Reichenbach; D. cathcartii J. D. Hooker; D. haemoglossum Thwaites; D. intermedium Teijsmann & Binnendijk.

Stem erect, tough, bamboolike, cylindric, to 1 m, 3-4 mm in diam., unbranched, with many nodes, internodes 2-2.5 cm, enclosed in leaf sheaths. Leaves arranged in 2 rows, narrowly lanceolate, ca. 15 × 2 cm, base contracted into a sheath, acuminate toward apex, apex ± hooked on one side; sheaths articulate at junction with blade. Inflorescence emerging through sheaths, apparently leaf-opposed, 1-4-flowered; peduncle very short, base with 2 or 3 bracts; floral bracts pale brown, shell-like, ca. 3 mm. Pedicel and ovary yellowish green, ca. 1.7 cm, slender. Flowers spreading, small; sepals and petals yellowish brown, lip purple, column and anther cap yellow. Dorsal sepal subelliptic, 8-9 × 3.5-4(or more) mm, 9-veined, obtuse to rounded; lateral sepals obliquely ovate-lanceolate, nearly as large as dorsal sepal, base adnate to column foot, apex obtuse to rounded; mentum ca. 6 mm. Petals suboblong, ca. as long as dorsal sepal, but slightly narrower, 3-veined, marginal veins branched, apex obtuse to rounded; lip obovate-elliptic, ca. 12 × 5 mm, adaxial surface with 1 central yellow ridge, with a long tapelike callus near apex, rounded, mucronate. Column ca. 4 mm; anther cap conic.

Epiphytic on tree trunks in forests, lithophytic on rocks in open forests; 600-1000 m. Hainan, SE Xizang (Mêdog), S Yunnan (Mengla) [Bhutan, India, Indonesia, Laos, Malaysia, Myanmar, Sri Lanka, Thailand, Vietnam].