Herbs perennial, glabrous, 30--65 cm tall. Stems erect, quadrangular and usually branched in upper part. Leaves opposite, often alternate in upper part of stem, sessile or petiole 5--10 mm; leaf blade lanceolate to elliptic-lanceolate or elliptic, 4--10 X 0.8--4 cm, base attenuate, margin obscurely repand, apex acute to acuminate; veins 4--6 pairs; veinlets inconspicuous. Racemes 5--15 cm, bracts linear-lanceolate, 3--5 mm. Pedicel 2--7 mm, elongating slightly in fruit. Calyx lobes linear-lanceolate, ca. 5 mm, hyaline margined, apex subulate-acuminate. Corolla white, 4--8 mm, parted 1/2--2/3; lobes ovate-oblong to spatulate or elliptic. Stamens included; filaments adnate to lower part of corolla lobes, free parts 2--2.5 mm; anthers linear, dorsifixed, ca. 1.5 mm, apex red glandular. Ovary glabrous; style to 5 mm. Capsule subglobose, ca. 3 mm in diam. 2n = 24.

* Damp woodland margins, streamsides, grassy mountain slopes, in scrub; 900--2500 m. Guizhou, Hubei, Hunan, Shaanxi, S Sichuan, Yunnan, Zhejiang