钻柱兰 zuan zhu lan

Sarcanthus rivesii Guillaumin, Bull. Soc. Bot. France 77: 330. 1930.

Stems to 1 m, ca. 7 mm in diam., often branched. Leaves elliptic, 3-4 × 1-1.5 cm, obtuse and unequally bilobed. Inflorescence 5-10 mm, 2-7-flowered; peduncle very short, with 2 or 3 papery short sheaths; floral bracts ovate-triangular, ca. 1.5 mm, obtuse. Flowers thickly textured, sepals and petals pale yellow with 2 or 3 brown stripes, lip pink; pedicel and ovary ca. 8 mm. Dorsal sepal subelliptic, ca. 4 × 2.2 mm, obtuse; lateral sepals ovate-oblong, broader, obtuse. Petals oblong, ca. 4 × 1.5 mm, obtuse; lip larger than sepals and petals, 3-lobed; lateral lobes erect, ovate-triangular, small, obtuse; mid-lobe broadly ovate-triangular, ca. 6 × 6 mm, base with a papillate callus on either side, apex slightly narrowed and obtuse; spur ca. 3 × 2.5 mm, interior with a longitudinal ridge on front wall gradually broader from entrance down to end, and with an elliptic appendage on back wall. Column ca. 2 mm, with dense white glandular long hairs on front sides. Fl. Oct.

Epiphytic on tree trunks or lithophytic on rocks in broad-leaved evergreen forests; 700-1100 m. W Guangxi, S and SW Yunnan [Laos, Vietnam].