西藏虎头兰 xi zang hu tou lan

Cyperorchis tracyana (L. Castle) Schlechter.

Plants epiphytic, autotrophic. Pseudobulbs ellipsoid-ovoid or oblong-ovoid, 5-11 × 2-5 cm, mostly enclosed in leaf bases. Leaves 5-8 or more, lorate, 55-80 × (1.5-)2-3.4 cm, articulate 7-14 cm from base, apex acute. Inflorescence arising from within sheaths at base of pseudobulb, arching or suberect, 65-100 cm or longer; rachis usually more than 10-flowered; floral bracts ovate-triangular, 3-5 mm. Flowers fragrant, 13-14 cm in diam.; pedicel and ovary 30-55 mm; sepals and petals yellowish green to olive-green, with irregular dark red-brown venation and spots; lip pale yellow to cream-yellow with dark red-brown venation on lateral lobes and with vertical dashes and scattered spots of same color on mid-lobe, lamellae cream and red spotted. Sepals narrowly elliptic, (45-)55-70 × 17-20 mm, apex acute; lateral sepals slightly oblique and twisted. Petals falcate, slightly twisted, 45-65 × 7-12 mm, apex acute; lip ovate-elliptic, 45-60 mm, base fused to basal margins of column for 4-5 mm, 3-lobed; lateral lobes erect; mid-lobe recurved, elliptic; disk long ciliate and with reddish brown hairs on veins of lateral lobes, sparsely ciliate on mid-lobe, with 2 central lamellae and with a row of long hairs 5-6 mm between lamellae; lamellae each with a row of long hairs 5-6 mm which extend to middle of mid-lobe. Column arcuate, 35-43 mm, winged, shortly hairy below middle on ventral surface; pollinia 2, deltoid, 3-4 mm. Capsule ellipsoid, 80-90 × 45-50 mm. Fl. Sep-Dec, fr. Feb-Mar. 2n = 40.

Tree trunks and branches in forests, rocks by streamsides; 1200-1900 m. SW Guizhou, SE Xizang, SE and SW Yunnan [Myanmar, N Thailand, N Vietnam].