Annuals to 60 cm tall. Roots yellow, ca. 5 mm in diam. Stems erect, subquadrangular, narrowly winged on angles, branched from base. Basal leaves withered at anthesis; petiole flattened, ca. 3 cm; leaf blade oblanceolate to elliptic, 2-3.5 × 1-1.5 cm, thin herbaceous, base narrowed, apex acute to obtuse, veins 5 and prominent. Stem leaves sessile, narrowly elliptic to ovate-lanceolate, 1.5-8 × to 2 cm, thin herbaceous, base obtuse and subamplexicaul, apex acuminate, veins 3-5. Inflorescences panicles of cymes, many flowered, spreading, to 27 cm. Flowers 4merous. Pedicel erect, 3-15 mm, to 2.5 cm for terminal flowers, slender. Calyx elongated in fruit, tube ca. 0.5 mm; lobes lanceolate to ovate-lanceolate, 2-3 mm, apex acute, veins 1-3 and indistinct. Corolla pale yellow-green, 3-5 mm in diam., tube ca. 0.5 mm; lobes ovate, 3-5 mm, apex acute and caudate. Nectaries 2 per corolla lobe, radially elongated, with a narrow scale and raised margin with many long fimbriae. Filaments ca. 2 mm; anthers ovoid, ca. 1 mm. Style distinct, linear, ca. 2 mm; stigma lobes capitate. Capsules ovoid, 7-9 mm. Seeds light brown, subglobose, ca. 0.7 mm; seed coat smooth. Fl. and fr. Aug.

* Hillsides, wet and shady valleys; 2500-2700 m. NW Yunnan.