尾丝钻柱兰 wei si zuan zhu lan

Sarcanthus bicuspidatus Rolfe ex Downie, Bull. Misc. Inform. Kew 1925: 391. 1925, not (J. D. Hooker) J. J. Smith (1912).

Stems elongate, branched. Leaves elliptic-oblong, often V-shaped-conduplicate, falcate in side view, 3-4 × ca. 1.4 cm, obtuse and unequally bilobed. Inflorescence ca. 5 mm, usually 2- or 3-flowered; peduncle ca. 5 mm, with 2 or 3 short sheaths; floral bracts ovate-triangular, 3-4 mm, acute. Flowers opening widely, whitish, with purplish red veins on sepals and petals, lip waxy yellow on disk, spur yellowish green, column white; pedicel and ovary yellowish green, 8-12 mm. Sepals similar, broadly elliptic, slightly concave, ca. 5 × 3 mm, acute. Petals oblong, ca. 4 × 2 mm, acute; lip spurred at base, 3-lobed; lateral lobes erect, ovate-triangular, small; mid-lobe subcordate, large, ca. 5 × 4 mm, shortly caudate and shallowly 2- or 3-lobed; spur ca. 5 × 3.5 mm, stout, with a longitudinal groove on front surface, interior with a longitudinal broad ridge almost dividing spur into 2 halves, and with an appendage on back wall. Column ca. 2 mm, with a cluster of short white glandular hairs on either side below middle. Fl. Jun-Oct.

Epiphytic on tree trunks or lithophytic on rocks in open forests; 800-1400 m. SW Guizhou, S and SE Yunnan [Thailand].