Shrubs (3-)5-6 m tall, erect to climbing. Branchlets, petioles, inflorescence rachises, and leaf veins rust colored hirsute. Branchlets terete, becoming yellowish brown to red-brown and subglabrous, nodes with an elevated leaf scar. Petiole 8-10 mm; leaf blade rhomboid-elliptic to ovate, 6-10 3.7-6 cm, subleathery, minutely hirsute especially on veins, base broadly cuneate to subrounded, margin entire or rarely obscurely serrulate, apex acuminate, acute, or rarely obtuse; veins 6 or 7 pairs, slightly elevated on both surfaces. Inflorescences racemelike thyrses; bracts lanceolate to ovate, sparsely minutely hispid. Calyx with a tube ca. 2 mm, 2-lipped; lips entire, sparsely minutely hirsute, glandular. Corolla white, 4-lobed, exserted from calyx, tube ca. 4 mm, outside sparsely glandular, inside puberulent, yellowish villous in throat. Stamens conspicuously exserted. Ovary glabrous. Styles shorter than stamens; stigmas 2. Fruit narrowly obovate, ca. 4 mm, apically glabrous. Fl. and fr. May-Jul.