A tall climber with slightly ribbed young shoots, covered with stout, curly, reddish bristles; the year-old wood glabrous; pith chambered. Leaves ovate or ovate-oblong, heart-shaped or rounded at the base, taper-pointed, minutely toothed, 3 to 5 in. long, 11⁄2 to 21⁄2 in. wide; glaucous beneath, with a little down on the midrib and veins. Leaf-stalk 3⁄4 to 11⁄2 in. long, bristly when young. Flowers white, nearly 1⁄2 in. diameter, produced in the leaf-axils in short, rounded racemes, the stout main-stalk reddish bristly, the slender individual flower-stalks downy, 1⁄4 to 1⁄2 in. long. Fruits cylindrical, 3⁄4 to 1 in. long, 1⁄3 to 1⁄2 in. wide.
Native of Yunnan, in mountain forests at 5,000 to 6,000 ft; discovered by Henry; introduced by Wilson for the Arnold Arboretum, and sent thence to Kew in 1910.