Description from Flora of China
Tropidia angulosa (Lindley) Blume var. nipponica (Masamune) S. S. Ying.
Plants to 60 cm tall. Rhizome ascending; roots filiform, often with small tuberlike nodules. Stem erect, slender, 20-50 cm, 3-4 mm in diam., often branched, proximal nodes enclosed in sheaths; sheaths to 4 cm. Leaves 1 or 2, alternate, elliptic or ovate-lanceolate, 10-16 × 4-8 cm, papery, apex acute. Inflorescence terminal, subglobose, ca. 6 cm, sparsely pubescent, 5-10-flowered; floral bracts lanceolate, 5-6 mm. Flowers not resupinate, off-white. Dorsal sepal ovate-lanceolate, ca. 7 × 3 mm, apex obtuse; lateral sepals almost completely connate and forming a synsepal; synsepal oblanceolate, 7-8 mm, apex 2-lobed. Petals elliptic, ca. 6 × 3 mm, apex acute; lip ovate-lanceolate, ca. 6 mm, base saccate, apex reflexed; disk pale yellow, thickened apically. Column suberect, ca. 3 mm, 3-lobed; anther ovoid, ca. 2.5 mm; caudicle slender; rostellum triangular, apex bifid. Fl. Jul.
Forests; low to mid elevations. Taiwan [S Japan (Ryukyu Islands)].