Herbs to 70 cm tall, spreading to erect. Stems slender, 4-angled, sulcate, slightly puberulent, usually rooting at basal nodes. Petiole 0.5-3 cm, pubescent; leaf blade ovate to oblong-lanceolate, 2.5-9 × 1.8-3 cm, membranous, glabrous except sparsely hirsute along veins, secondary veins 5 or 6 on each side of midvein, base cuneate to attenuate, margin entire or slightly undulate, apex acute to obtuse. Spikes terminal or axillary, 1-7 cm, 2-sided; bracts 4-ranked, all fertile, elliptic, 7-8 × 2-4 mm, margin sparsely ciliate, apex acute; bracteoles elliptic, 4-5 × ca. 2.5 mm, margin membranous and sparsely ciliate, apex mucronate. Calyx deeply 5-lobed; lobes linear-lanceolate, ca. 5 mm. Corolla bluish, 6-8 mm, outside slightly pilose and glandular punctate; lower lip 3-lobed, lobes ca. 7 mm; upper lip shallowly dentate. Ovary subglabrous; style ca. 1 cm, glabrous; stigma obtuse. Capsule ovoid, ca. 6 mm, 4-seeded. Seeds lenticular, ca. 1.5 mm wide, minutely tuberculate. Fl. Sep-Oct, fr. Nov-Dec.

This species is used medicinally.

Grasslands; 300-1200 m. Anhui, Fujian, Guangdong, Guangxi, Jiangxi, Taiwan, Zhejiang [Vietnam].