Herbs perennial, becoming black when dry. Stems decumbent, to 45 cm, terete, much branched, glabrous. Leaves opposite; petiole 0.8--1.5 cm; leaf blade broadly ovate to ovate, 1.5--2.5 X 1--2 cm, abaxially glabrous, black glandular punctate near margin, adaxially sparsely bristly, base rounded to truncate, apex acute to obtuse. Pedicel 5--10 mm, densely glandular. Flowers solitary or paired in axils of leaves. Calyx ca. 4 mm, parted nearly to base; lobes linear-lanceolate, abaxially cristate; crest ca. 0.5 mm, glabrous. Corolla ca. 6 mm; tube ca. 2 mm; lobes elliptic, black glandular punctate, sparsely short glandular striate, apex obtuse. Filaments connate basally into a ca. 2 mm high tube, free parts ca. 1 mm; anthers oblong, dorsifixed, opening by lateral slits, ca. 1 mm. Ovary globose, glabrous; style slightly longer than stamens. Capsule unknown. Fl. Apr-May.

* Grassy banks near rice paddies. Guangxi (Yangshuo Xian).