63. Dendrobium wattii (J. D. Hooker) H. G. Reichenbach, Gard. Chron., ser. 3,. 4: 725. 1888.
高山石斛 gao shan shi hu
Dendrobium cariniferum H. G. Reichenbach var. wattii J. D. Hooker, Bot. Mag. 109: ad t. 6715. 1883; Callista wattii (J. D. Hooker) Kuntze.
Stems sometimes curved, cylindric, equally thick above and below, 12-60 cm, 4-9 mm in diam., rigid, unbranched, with many nodes, internodes 3-5 cm, with longitudinal ribs. Leaves several to 10, along middle and upper part of stem, oblong, 5-9 × 1-2 cm, leathery, abaxially black hirsute when young, base decurrent forming clasping sheaths, apex obtuse and slightly unequally 2-lobed; leaf sheath densely black hirsute. Inflorescence apical on leafy stem, 1- or 2-flowered; peduncle ca. 5 mm; basal sheaths 3 or 4, broadly ovate, 5-10 mm; floral bracts triangular, 7-13 × 6-7(or more) mm, abaxially with dense black rigid hairs, apex acute. Pedicel and ovary 3-4 cm. Flowers spreading, usually less than 3 cm in diam., white, lip with yellow veins on lateral lobes, disk with a yellow patch. Dorsal sepal oblong, ca. 24 × 7-10(or more) mm, 5- or 6-veined, apex acute; lateral sepals obliquely lanceolate, upper margin ca. as long as dorsal sepal, lower margin 40-50 × 8-11(or more) mm, 7- or 8-veined, apex acute; mentum long and narrow, straight, ca. 25 mm, forming spur. Petals oblanceolate, ca. 40 × 32 mm, 7- or 8-veined, bluntly rounded and mucronate; lip ca. 35 mm, less than 30 mm wide across lateral lobes when flattened; lateral lobes obovate, embracing column, front margin slightly undulate; mid-lobe orbicular, 11-15 mm wide, margin irregularly serrate, truncate, usually minutely mucronate, with only an indistinct sinus; disk with a broad median callus splitting into 4 or 5 parallel small keeled ridges extending from base of lip to base of mid-lobe. Column ca. 6 mm; teeth triangular, ca. 2 mm; anther cap subspherical, front margin denticulate, apex slightly concave.
Epiphytic on tree trunks in dense forests; ca. 2000 m. S Yunnan (Jinghong, Mengla) [NE India, Myanmar, N Thailand, Vietnam].
This species has been misidentified as Dendrobium infundibulum Lindley (e.g., in FRPS 19: 131. 1999), which was originally described from Myanmar (Moulmein).