74. Dendrobium pseudotenellum Guillaumin, Bull. Mus. Natl. Hist. Nat., sér. 2. 36: 697. 1965.
针叶石斛 zhen ye shi hu
Ceraia pseudotenella (Guillaumin) M. A. Clements.
Stems erect, rigid, slender, basal 2 internodes swollen to forming fusiform pseudobulb, others cylindric, 30-43 cm, ca. 2 mm in diam., unbranched, with many nodes, internodes 1-3.5 cm, yellowish brown when dry, glossy. Leaves sparsely distichous, ascending, subterete, slender, 3-9 cm, less than 1 mm wide, fleshy, base with tightly clasping sheaths, apex acute. Peduncle ca. 2 mm; basal sheaths 4 or 5, overlapping; floral bracts ovate, ca. 1.5 mm, acute. Pedicel and ovary ca. 5 mm, slender. Flowers very small, thin, white. Dorsal sepal oblong, ca. 6 × 2.2 mm, 3-veined, obtuse; lateral sepals obliquely ovate-triangular, much larger than dorsal sepal, base very oblique, apex slightly acute; mentum narrowly conic, ca. 9 mm, obtuse. Petals oblong, ca. 6 × 2 mm, 3-veined, obtuse; lip obovate, ca. 11 × 7 mm, margin lacerate-fimbriate, apex 3-lobed; lateral lobes erect; mid-lobe nearly transversely oblong, apex concave; disk with 3 central ridged projections, dilated into plicate ridges at base of mid-lobe. Column ca. 2 mm, foot ca. 8 mm, with a basal callus; anther cap nearly glabrous, apex subtruncate.
Epiphytic on tree trunks in mountain forests; ca. 900 m. S Yunnan (Mengla) [Vietnam].