Shrubs climbing. Stems terete, striate, densely yellow-brown villous, with elongate internodes. Petiole 3-5 cm, yellow-brown villous; leaf blade ovate, 5-13 × 4-8 cm, leathery, abaxially densely gray or yellow-brown villous, adaxially densely gray or yellow-brown villous when young, glabrescent, veins palmate, 3-5 pairs from base, base deeply cordate, sinus 5-10 × ca. 0.5 cm, apex acute. Flowers in axils of leafy shoots, solitary. Pedicel pendulous, 3-6 cm, grayish pilose; bractlets ovate, 3-5 × 3-4 mm, inserted on basal 1/2 of peduncle. Calyx purple-red; tube geniculately curved, abaxially villous to glabrous; basal portion of tube 10-15 × 7-10 mm; limb subcylindric, 1.5-2.5 × 1-1.5 cm, 3-lobed; lobes slightly unequal, subrounded or lower lobe nearly truncate. Anthers oblong, ca. 2 mm. Gynostemium 3-lobed. Capsule cylindric, undulately 6-angled, ca. 6 × 2 cm, dehiscing basipetally. Seeds narrowly ovoid, ca. 6 × 4 mm. Fl. Apr-May, fr. Jun-Aug.

* Thickets, forests; 1000-1600 m. Guizhou, Sichuan, Yunnan.