Description from
Flora of China
Herbs perennial, 20--35 cm tall. Stems erect or arcuate at base, quadrangular, simple or weakly branched, pubescent or glabrous. Leaves opposite, upper 2 or 3 pairs crowded; petiole indistinct in upper leaves, to 3 cm in lower leaves; leaf blade lanceolate, 4--9 X 1--2.5(--3) cm, abaxially pilose or glabrescent, sparsely transparent glandular punctate, adaxially sparsely bristly, base attenuate, apex acuminate; veins 3--5 pairs; veinlets inconspicuous. Inflorescences terminal, capitate, 6--10-flowered; bracts elliptic to lanceolate, ca. as long as calyx. Pedicel 1--2.5(--5) mm. Calyx lobes lanceolate, 0.9--1.5 cm, apex acuminate-subulate, costate. Corolla yellow, 0.9--1.3 cm; lobes ovate-oblong, transparent glandular punctate, apex rounded to apiculate. Filaments connate basally into a 4--5 mm high tube, free parts 3--5 mm; anthers ovate-lanceolate, dorsifixed, opening by lateral slits, 1.5--2 mm. Ovary ovoid; style ca. 8.5 mm. Capsule subglobose, 3--3.5 mm in diam.
* Open forests, valley trailsides, damp areas in forests, streamsides; 500--1700 m. N Guangdong, Guangxi, Guizhou, W Hubei, Hunan, S Jiangxi, E Sichuan, NE Yunnan