罗河石斛 luo he shi hu

Stems cylindric, to 80 cm, 3-5 mm in diam., slightly rigid, with many nodes, internodes 13-23 mm, upper nodes bearing roots and new shoots (keikis), golden yellow when dry, with several longitudinal ridges. Leaves borne in 2 rows, oblong, 3-4.5 × 0.5-1.6(or more) cm, leathery, with clasping sheaths at base, apex acute; sheath sparsely clasping when dry, sheath mouth often open. Inflorescences 1-flowered, arising laterally on top of stem or axillary, erect; peduncle absent; floral bracts broadly ovate, small, ca. 3 mm, waxy, apex acute. Pedicel and ovary to 15 mm; ovary often clavate. Flowers spreading, waxy yellow, slightly fleshy. Dorsal sepal elliptic, ca. 15 × 9 mm, 7-veined, bluntly rounded; lateral sepals obliquely elliptic, slightly longer than dorsal sepal, but relatively narrow, 7-veined, obtuse; mentum subglobose, ca. 5 mm. Petals elliptic, ca. 17 × 10 mm, 7-veined, bluntly rounded; lip entire, obovate, ca. 20 × 17 mm, base cuneate and both sides embracing column, front margin irregularly denticulate. Column ca. 3 mm, apex with 2 teeth on either side; anther cap subspherical, glabrous, margin denticulate, apex subtruncate and reflexed upward. Capsule elliptic-globose, ca. 4 × 1.2 cm.

● Mountain valleys, lithophytic on rocks at forest margins; 1000-1500 m. Chongqing, N Guangdong, SE Guangxi, W Guizhou, W Hubei, Hunan, SE Yunnan.

One of us (H. P. Wood) notes that the plant described in the protologue of Dendrobium lohohense is very similar to D. henryi, and the two taxa may be conspecific.