Annuals 30-40 cm tall. Roots yellow, fibrous. Stems erect, subquadrangular, branched. Leaves sessile, linear to linear-lanceolate, 1.5-6 cm × 2-5 mm, base narrowed, margin slightly revolute, apex acuminate, midvein distinct. Inflorescences panicles of cymes, lax, spreading branched, many flowered, to 30 cm. Flowers 5merous. Pedicel erect, to 3 cm, slender, subquadrangular. Calyx tube 1-2 mm; lobes linear to linear-oblong, 2-5 mm, unequal, apex obtuse, midvein slender. Corolla white, with yellow-green spots, 3-8 mm in diam., tube 1-2 mm; lobes elliptic-lanceolate, 5.5-6.5 mm, apex acuminate and apiculate. Nectaries 2 per corolla lobe, yellow-green, orbicular, reduced to a naked gland patch. Filaments ca. 3.5 mm; anthers ellipsoid, ca. 1 mm. Style short, distinct; stigma lobes capitate. Capsules narrowly ovoid, ca. 8 mm. Seeds brown, ellipsoid to globose, 1-1.5 mm in diam.; seed coat warty. Fl. and fr. Aug-Sep.

* Slopes, scrub; ca. 1500 m. Guizhou, W Hubei, E Sichuan.