9. Dendrobium sulcatum Lindley, Edwards’s Bot. Reg. 24: ad t. 65. 1838.
具槽石斛 ju cao shi hu
Callista sulcata (Lindley) Kuntze.
Stem pseudobulbous, erect, clavate, compressed, narrowed toward base, 24-38 cm, 3-4 mm in diam. below, 1-2.5 cm in diam. at widest point, grooved, unbranched, nodes several, with longitudinal stripes, internodes 2-5 cm, with a membranous sheath, yellowish brown and glossy when dry. Leaves 3 or 4, subterminal, sessile, distichous, broadly elliptic to elliptic-ovate, 18-21 × ca. 4.5 cm, papery, apex acute. Inflorescence axillary, adjacent to leaf, subdensely 5-10-flowered; peduncle 2.5-3 cm, rachis short; basal sheaths 3 or 4, overlapping at base, distant above, ovate, 3.5-5 × 2-3 mm, membranous, 3-veined, subacute; floral bracts ovate, 3-4 × 2-3 mm, membranous, 3-veined, apex acute. Pedicel and ovary ca. 2.5 cm, slender. Flowers thin, uniformly golden yellow, lip with red-purple markings or stripes at base. Dorsal sepal oblong, ca. 25 × 9 mm, 5- or 6-veined, apex subacute; lateral sepals nearly equal to dorsal sepal; mentum conic, ca. 5 mm, broad and obtuse. Petals subobovate, ca. 24 × 11 mm, 5-veined, base contracted into a short claw, margin entire, apex acute; lip suborbicular to wedge-shaped, incurved, 18-20 × ca. 20 mm, adaxial surface densely pubescent near margin, base shortly clawed, margin minutely erose to ciliate-hairy, apex emarginate. Column ca. 5 mm; anther cap backward and forward compressed, subglobose or conic, glabrous, front margin ± irregular, apex emarginate.
Epiphytic on tree trunks in dense forests; 700-800 m. S Yunnan (Mengla) [NE India, N Laos, Myanmar, N Thailand].