Herbs perennial, 20--60 cm tall, rust-colored strigillose throughout. Stems erect, nearly terete in lower part, obtusely quadrangular in upper part, simple or weakly branched. Leaves opposite; petiole 1--3 cm, auriculate and semi-clasping at base; leaf blade elliptic-ovate, 3--7.5 X 1.5--4 cm, base broadly cuneate to subrounded, apex acute; veins 4--6 pairs, slightly raised abaxially; veinlets invisible. Racemes axillary, 4--10-flowered; peduncle 1--4 cm; bracts narrowly lanceolate, 5--8 mm, ± adnate to base of pedicel. Pedicel 2--5 mm. Calyx lobes lanceolate, 5--7.5 X ca. 1.5 mm, costate. Corolla yellow, slightly longer than calyx; tube ca. 1 mm; lobes 6--8 X 3--4 mm, sparsely transparent glandular, apex acute. Filaments connate basally into a 2--2.5 mm high tube, free parts 2--3.5 mm; anthers oblong, dorsifixed, opening by lateral slits, ca. 1 mm. Ovary sparsely strigillose; style 4--5 mm. Capsule subglobose, ca. 3 mm in diam. Fl. May-Jun.

Mountain valleys, streamsides; 600--1700 m. W Guangxi, SE Yunnan [N Vietnam].