Gastrodia angusta S. Chow & S. C. Chen Acta Bot. Yunnan. 5: 363. 1983.

原天麻 yuan tian ma

Plants 40-60(-80) cm tall. Rhizome grayish white, ellipsoid-fusiform, 5-10(-15) cm, stout, 3-5 cm in diam., densely noded, fleshy, with scales at nodes. Peduncle 25-35 cm, with a few scattered scales at base; rachis 15-25 cm, 20-30-flowered; floral bracts elliptic, 7-8 mm, much shorter than ovary, apex acuminate. Flowers suberect, resupinate, cream-white; pedicel and ovary 10-12 mm. Perianth tube urceolate, 10-12 mm, with a deep sinus between lateral sepals, base inflated, outer surface smooth; free portion of dorsal sepal ovate to suborbicular, ca. 3 mm, margin involute, apex obtuse; free portion of lateral sepals obliquely triangular, 6-7 mm, margin involute, apex obtuse to acute; free portion of petals concave, ovate, ca. 2.5 mm, apex obtuse to acute; lip simple, oblong-rhombic, ca. 15 × 5-6 mm, glabrous, base shortly clawed, margin erose toward apex; claw with a pair of lunar calli at base; disk with 2 yellowish, slightly raised longitudinal ridges. Column 7-8 mm; column foot short; stigma linear, narrow. Capsule obovoid, ca. 20 × 7-8 mm. Fl. and fr. Mar-Apr. 2n = 36*.

● 1600-1800 m. NW and SE Yunnan.