Description from Flora of China
Annuals 30-90 cm tall, whole plant puberulent. Roots yellow, fibrous. Stems erect, 2-3 mm in diam., striate, branched. Leaves sessile, ovate-lanceolate, 2-6 × 0.4-1.5 cm, base cordate and subamplexicaul, apex acute, veins 3-5. Inflorescences panicles of cymes, many flowered, spreading. Pedicel 0.5-2 cm, terete, with puberulent striae. Flowers nodding, 5merous, 1.5-2 cm in diam. Calyx tube 1-1.5 mm; lobes bractlike, apically acute, 3-7-veined, unequal; 2 larger lobes ovate-lanceolate, 1-2 × to 1.5 cm; 3 smaller lobes linear-lanceolate to lanceolate, 8-10 × ca. 5 mm. Corolla white, with 2 blackish purple spots above each nectary, these sometimes joined into a ± continuous ring; tube 1-1.5 mm; lobes ovate-oblong, 1-1.5 cm, lacerulate, apex obtuse. Nectaries 1 per corolla lobe, horseshoe-shaped, naked. Filaments 7-9 mm, basally much enlarged but free, puberulent; anthers dark purple, narrowly ellipsoid, 2-2.5 mm. Ovary ovoid-ellipsoid, 8-9 mm. Style 3-4 mm, slender; stigma lobes capitate. Fl. Aug-Nov.
* Beside streams, hillsides, scrub; 2800-4100 m. NW Yunnan.