Thrixspermum segawai Masam.
Plants without leaves. Stem absent. Roots to 35 cm long, 2-4 mm thick, grayish green, glabrous. Racemes usually pendulous or curved, 5-12 cm long; peduncle brownish, pubescent, with a few sheath-like scales; rachis slightly thicker, densely pubescent; bract ovate to triangular, membranaceous, 3-5 mm long, acute to acuminate, glabrous or sparsely pubescent; pedicel and ovary 4-5 mm long, pubescent. Flowers 6-15, +/-spreading, pale yellow or yellow to pale green, sometimes tinged with brown or with irregular brownish red patches near base of sepals and petals; dorsal sepal elliptic to ovate, 4-5.5 mm long, 3.5-4 mm wide, apex obtuse to rounded, slightly contracted at base, sparsely pubescent near base of outer surface, lateral ones broadly elliptic or ovate, 4.5-6 mm long, 3.5-4 mm wide, slightly oblique, glabrous inside, sparsely pubescent near base outside; petals elliptic to nearly rectangular, 4-6 mm long, 3.5-4 mm wide, obtuse to truncate at apex, not contracted at base; lip 5-6 mm long, shallowly saccate at base, lateral lobes erect, falcate, 3 mm long, obtuse to truncate at apex, with brownish streaks inside and spots outside, midlobe short, thick, whitish, fused with a bilobed callus extending into sac; sac short conic, 2-3 mm long, often marked with few to many spots outside, longitudinal callus of disc pubescent, often canaliculate, running to bottom of sac and extending to back wall; column stout, 1.5-2 mm long, foot 3 mm long, sometimes with spots, pubescent outside; anther cap yellowish, oval, 1 mm across, with filiform appendages ca. 2 mm long; pollinia 0.5 mm in diam., stipe tape-like, viscidium squared. Capsules 4 cm long, distinctly ridged, pubescent.
HSINCHU: Mupiruii, Segawa s. n. Jul 1933. TAICHUNG: Chiapaoutai, Su et al. 8191*, 8916. KAOHSIUNG: Wanshan, Su & Chen 8956; Sanping, Su 9597.
Endemic, in forests below 1,500 m in central to southern mountainous regions.
Although the size and structure of the flowers is rather consistent, they vary greatly in color. Brownish patches on the sepals and petals are sometimes totally absent. When present, these patches may be in pale to dark and they vary form small spots to large patches. In extremes, the large patches merge and there is only the yellowish band along the margins of the sepals and petals.