Description from Flora of China
Herbs perennial, erect, 20--45 cm tall. Stems 1 to many, quadrangular; branches usually many, short. Leaves alternate; petiole 2--5 mm; leaf blade ovate to rhomboid-ovate, 1--17 X ca. 8 mm, abaxially glabrous, adaxially ± appressed bristly pubescent, especially near margin, base cuneate-attenuate, apex acute to apiculate; veins 2 or 3 pairs; veinlets inconspicuous. Leaves of short branches 3--4 X smaller. Pedicel 3--7 mm. Flowers solitary, in axils of branch leaves. Calyx 3--4 mm; lobes narrowly lanceolate, glandular on margin and inside. Corolla yellow, deeply parted; lobes ovate-lanceolate, ca. 3.5 X 1.1 mm, apex acute. Filaments very short, anthers ca. 2.5 mm, basifixed, apex obtuse, opening by apical pores. Ovary ovoid, style ca. 3.5 mm. Capsule unknown.
* Valleys of mountains, stream banks; ca. 600 m. NW Guangxi.