Description from Flora of China
Annuals 20-45 cm tall. Roots yellow, stout. Stems erect, 2-3 mm in diam., subquadrangular, narrowly winged on angles, branched. Basal leaves withered at anthesis. Stem leaves sessile, lanceolate to ovate-lanceolate, 2-3.2 cm × 6-10 mm, base obtuse and subamplexicaul, margin ciliolate and slightly revolute, acute, veins 3. Inflorescences panicles of cymes, many flowered, spreading. Flowers 5merous. Pedicel erect, 0.5-2.5 cm, subquadrangular. Calyx tube 1-1.5 mm; lobes lanceolate, 6-11 mm, margin ciliolate and slightly revolute, apex acuminate and apiculate, veins 3. Corolla yellow, 1.5-1.7 cm in diam., tube 2-3 mm; lobes ovate-lanceolate, 1-1.3 cm, apex acuminate and apiculate. Nectaries 2 per corolla lobe, radially elongated, with a narrow scale and raised margin with many long fimbriae. Filaments 4-5 mm; anthers ellipsoid, 1.5-2 mm. Ovary ovoid-ellipsoid, 5-8 mm. Style indistinct; stigma lobes capitate. Fl. Sep-Nov.
* Hillsides. Yunnan (Binchuan Xian).