A small deciduous tree; young shoots covered with minute stellate down. Leaves mostly obovate and tapered at the base, sometimes roundish; coarsely and unevenly toothed (or almost lobed) above the middle, entire towards the base; 11⁄2 to 4 in. long, 1 to 3 in. wide, stellately downy beneath, more especially on the midrib, thinly so elsewhere; veins in six to eight pairs; stalk 1⁄8 to 1⁄2 in. long. Flowers white, very shortly stalked, produced during June in racemes of eight or ten that terminate young, leafy, lateral shoots and are about 21⁄2 in. long. Corolla 5⁄8 to 3⁄4 in. long, funnel-shaped, five-lobed, the lobes ovate, pointed and about half as long as the tubular part, downy. Calyx bell-shaped, with five triangular, sometimes bifid, lobes, thickly covered with tawny down. Fruit globose to egg-shaped, 1⁄2 in. long.
Native of Japan, where it is said to be sparingly distributed. This is a very distinct species, firstly in the tube of the corolla being twice as long as the lobes (usually it is shorter) and, secondly, in the shape of the leaves with their broad ends and deep toothing. They bear a considerable resemblance to those of Hamamelis japonica. S. shiraiana was introduced to the USA in 1915 but did not reach Britain until some thirty years later and is still too rare in gardens for its merits to be assessed.