Herbs perennial, 10--30 cm tall. Stems prostrate, rooting at nodes; branches ascending to 20 cm. Leaves opposite, upper 2 pairs closely crowded; petiole ca. 1/2 as long as to ca. as long as leaf blade; leaf blade broadly ovate to suborbicular, rarely subelliptic, 1.3--3.8 X 0.8--3 cm, pilose or glabrous, transparent glandular striate near margin, stripes visible under transillumination, base broadly truncate, rarely cuneate, apex obtuse, rounded, or occasionally slightly emarginate. Uppermost 2 leaves usually much smaller. Pedicel 0.6--2.5 cm, pubescent or glabrous. Flowers 2--4, crowded at apex of stems and branches, without bracts. Calyx lobes lanceolate, 6--7 X 1--1.5 mm, narrowly hyaline margined. Corolla yellow; tube 2--3 mm; lobes oblong, 10--11 X 3--5 mm, sparsely transparent glandular striate, stripes becoming brownish when dry, adaxially dull red at base, apex obtuse. Filaments connate basally into a 2--3 mm high tube, free parts 4--6 mm; anthers oblong-ovate, dorsifixed, opening by lateral slits, ca. 1.5 mm. Ovary ovoid; style ca. 6 mm. Capsule subglobose, ca. 4--5 mm in diam. Fl. May-Jun.

* Thin mixed forests, streamsides; 500--1000 m. Anhui, Fujian, Guangdong, Hubei, Hunan, Jiangxi, Zhejiang.