Description from Flora of China
Aerides arachnites (Blume) Lindley; Dendrobium auriferum Lindley; Dendrocolla arachnites Blume; Sarcochilus arachnites (Blume) H. G. Reichenbach; S. aurifer (Lindley) H. G. Reichenbach; S. centipeda (Loureiro) Náves; S. hainanensis Rolfe; Thrixspermum arachnites (Blume) H. G. Reichenbach; T. auriferum (Lindley) H. G. Reichenbach; T. hainanense (Rolfe) Schlechter.
Stems ascending or pendulous, ± compressed terete, to 20 cm, stout, rigid, with many nodes, internodes 1-1.5 cm. Leaves many, oblong, 6-24 × 1-2.5 cm, slightly fleshy, base narrowed, apex obtuse and unequally bilobed. Inflorescences often several, solitary or in pairs, opposite to leaves, spreading or ascending, longer or shorter than leaves, few flowered; peduncle compressed, often narrowly winged; floral bracts persistent, densely spaced, 1-2 mm apart from each other, distichous, conduplicate, ca. 6 mm, fleshy. Flowers white or creamy yellow, turning yellow later, not opening widely, lasting almost 3 days, thickly textured; pedicel and ovary white, ca. 7 mm. Sepals narrowly falcate-lanceolate, 3-4.5 × 0.3-0.5 cm, long acuminate; lateral sepals slightly wider at base. Petals narrowly falcate-lanceolate, slightly smaller than sepals; lip shallowly saccate at base, 3-lobed; lateral lobes erect, subovate, 2-3 mm, obtuse; mid-lobe spreading, ca. 5 mm, thickly fleshy, conduplicate and narrowly conic in outline, obtuse; disk with a central callus. Column 1.5-2 mm, stout, foot very short. Fl. Jun-Jul. 2n = 38.
Epiphytic on tree trunks in forests; 100-1200 m. Guangxi, Hainan, Hong Kong, S and SE Yunnan [Cambodia, NE India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam].