Rhizome branched, terete, 3--5 mm thick, densely noded. Stem erect, purple-brown spotted, 25--35 cm, glabrous. Leaves 7 or 8, alternate; petiole 2--5 mm; leaf blade oblong-lanceolate to ovate-elliptic, 4--10 × 2--3.5 cm, glabrous, base obtuse-cuneate, apex acute-obtuse to acuminate. Inflorescences 1-or 2-flowered; peduncle 1.5--5 cm; bracts small, caducous. Pedicel 5--10 mm. Perianth yellowish white, cylindric or campanulate-cylindric, 2--2.5 cm; lobes deltoid, 2--3 mm. Filaments compressed, 7--8 mm, densely white-villous; anthers oblong, ca. 4 mm. Ovary ca. 4 mm. Style 1.4--1.6 cm. Fl. May--Jun.