Small annual herbs, 5–30 cm tall; stems erect, lax-branched, quadrangular, distinctly ribs with sparsely hirsute. Leaves pinnately nerved; petiolate, 5–12 mm long, glabrescent or sparsely hirsute, lamina ovate or elliptic, 1–4 x 0.7–2.5 mm, apex acute, base cuneate or obtuse, margins serrate, sparsely hirsute. Inflorescences terminal umbel with 2–5 flowers; pedicel 3–22 mm long, glabrous; bract leaf-like. Calyx campanulate, 4–6 mm long, 5-lobed; lobes shallowly, acute, veined, distinctly ridges or narrowly winged, glabrous except hirsute hair along ridges. Corolla white, 7–12 mm long; upper lip ovate, emarginsate, punctuate on margins, 2–3 mm wide; lower lip broadly 3-orbicular lobes, 6–8 mm wide. Stamens 4, all fertile; posterior filaments straight, glabrous, 1.2‒1.7 mm long; anterior filaments obscurely knob at base without spur. Capsules ellipsoid or ovoid, 4–5 x 3 mm, enclosed within or shorter than calyx lobes. Seeds numerous, ellipsoid, 0.36‒0.58 x 0.34‒0.48, scrobiculate-sulcate
China
Exposed areas in evergreen forests, 900‒1,500 m altitudes.