Annuals 15-80 cm tall. Roots yellow, stout. Stems erect, 2-7 mm in diam., subquadrangular, narrowly winged on angles, branched. Basal leaves withered at anthesis. Stem leaves sessile, linear-lanceolate, lanceolate, or narrowly elliptic, to 6 × 1.8 cm, base narrowed, apex acuminate to acute, veins 1-3 and prominent. Inflorescences panicles of cymes, many flowered, spreading. Flowers 5merous. Pedicel erect, to 3.2 cm, subquadrangular. Calyx tube 1-1.5 mm; lobes linear-lanceolate to lanceolate, 4-7 mm, apex acuminate to acute, midvein distinct. Corolla yellow or dark purple, 0.8-1.2 cm in diam., tube 1-1.5 mm; lobes lanceolate, 6-10 mm, apex acuminate and apiculate. Nectaries 2 per corolla lobe, radially elongated, with a narrow scale and raised margin with many long fimbriae. Filaments 4-6 mm; anthers ellipsoid, 1.5-2 mm. Style indistinct; stigma lobes capitate. Capsules ovoid-ellipsoid, 1.2-1.5 cm. Seeds pale yellow, ellipsoid, 0.5-0.6 mm; seed coat warty. Fl. and fr. Aug-Nov.

* 400-3800 m. Guizhou, W Hubei, Hunan, Sichuan, Yunnan