Perennial, glabrous or glabrescent climbing herb, up to 1 m. or more. Stems much branched, forked, pale-green. Leaves up to 5.5 x 4 (-5) cm., petiolate, broadly ovate to ovate-lanceolate, more or less truncate at base, obtuse to acute at apex, obscurely sinuate-repand at margin. Panicles terminal and axillary, loose, composed of remote, pedunculate or sessile 3-5-flowered whorls. Bracts small and narrow. Pedicels longer or shorter than flowers. Flowers 3-4 mm. Perianth campanulate to funnel-shaped and pink above, tubular and greenish below, puberulent; limb 2-3 mm. broad. Stamens 2, slightly exserted. Fruit about 5-7 mm., obscurely ribbed, glandular, with reddish brown tubercles in ring-like rows. Fl. March-May.