Plants perennial, glabrous, 50--100 cm tall. Stems erect, woody, quadrangular in upper part, usually much branched. Leaves alternate, crowded toward apex of young shoots, forming many interrupted whorls on stem; petiole 2--4 mm; leaf blade oblanceolate, 20--40 X 4--10 mm, subleathery, abaxially ± minutely glandular, adaxially with minute sunken dots, base attenuate, margin narrowly revolute, apex acute; midvein raised abaxially, impressed adaxially; veinlets obscure. Pedicel 1--2 cm. Flowers solitary, axillary. Calyx lobes ovate, ca. 5 mm, glandular on margin and inside, apex caudate-acuminate. Corolla yellow, 6--7 mm, deeply parted; lobes oblong, 5--6 X 3--4 mm, apex obtuse. Filaments connate basally into a ca. 0.5 mm high ring, fused with corolla, free parts ca. 0.6 mm; anthers ca. 4 mm, basifixed, opening by apical pores. Style ca. 4 mm. Capsule globose, 3--4 mm in diam., shorter than calyx. Fl. Apr-May.

* Mixed forests and scrub, on calcareous formations; 1400--1800 m. SE Yunnan.