Like many genera of the Witch Hazel family, Sinowilsonia consists of a single species. Leaves alternate, deciduous, pinnately veined. Flowers without petals, unisexual, inconspicuous, the males in leafless catkin-like racemes, with five sepals and five stamens. Females with a stellately downy receptacle (calyx-tube) which encloses the ovary and is surmounted by five spreading sepals; they are arranged in racemes which are terminal on leafy shoots and at first about 1 in. long, greatly lengthening as the fruits ripen. The fruit is a capsule, partly enclosed by the receptacle and containing numerous black seeds.
The genus is named after the famous plant collector E. H. Wilson, who collected some of the specimens from which the genus was described, and introduced its one species.