Plants 20-100 cm tall. Stems erect, apically branched, 4angled. Leaves sessile, ovate-lanceolate to ovate, 1-5 × 0.8-2.5 cm, base rounded, nearly clasping, and decurrent into narrow wings on stem, apex acute; veins 3-5, abaxially prominent. Pedicel 3-10 mm. Calyx 5-6 mm; lobes ovate, margin broadly membranous, apex caudate, midvein keeled. Corolla mauve-blue to lilac, 1.5-2.5 cm; tube cylindric, 4-6 mm; lobes elliptic, 1.1-1.7 cm, margin entire, apex short acuminate. Filaments linear, 1.5-2 mm; anthers 5.5-6.5 mm. Style linear, 1-1.2 cm; stigma lobes orbicular. Capsules subglobose, 4-5 mm in diam. Seeds ellipsoid, 0.7-1 mm. Fl. and fr. Jul-Sep.

Roadsides, meadows; 200-1500 m. Guangdong, Guangxi, Guizhou, Jiangxi, Yunnan [Cambodia, India, Laos, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Sikkim, Vietnam; Australia].