Malleola dentifera J. J. Smith Bull. Jard. Bot. Buitenzorg, sér. 3. 9: 191. 1927.

槌柱兰 chui zhu lan

Stems pendulous, slightly flattened terete, 3-10 cm, 3-4 mm in diam., unbranched, internodes 5-10 mm. Leaves many; leaf blade narrowly oblong, 4-7.5 × 0.5-1 cm, leathery, unequally bilobed or somewhat praemorse. Inflorescences borne opposite leaves, shorter than leaves, many flowered; floral bracts narrowly lanceolate, 1-2 mm. Flowers ca. 8 mm in diam., sepals and petals pale brownish yellow with 2 crimson stripes, lip purple and white, anther cap purple; pedicel and ovary ca. 8 mm. Dorsal sepal cymbiform, ovate, ca. 3 × 2 mm, acute; lateral sepals obliquely ovate, ca. 3 × 2 mm, ± concave. Petals oblong, ca. 3 × 1.5 mm, acute; lip spurred, 3-lobed; lateral lobes erect, broadly ovate-triangular, ca. 1 × 1 mm, with 3 triangular lobules at apex; distal lobule smaller, with thickened and incurved apical margin; mid-lobe recurved, narrowly lanceolate, fleshy thickened in basal half, narrowed toward apex, with a longitudinal groove from base to middle; spur subconic-oblong, ca. 5 × 2-3 mm, narrowed near tip. Capsule narrowly ovoid, 1-1.5 cm × 4-5 mm. Fl. Jul, fr. Aug-Sep.

Epiphytic on tree trunks in forests; 600-700 m. S Hainan, S Yunnan [Indonesia, Malaysia, Thailand, Vietnam].