Halesia L. (1759), in the family Styracaceae, the snowdrop tree or silverbell, contains 5 species. Description Trees to 28m, or shrubs. The leaves are alternate, deciduous, shallowly toothed. The flowers are white and hang down along the branches. Sepals form a cup with 4 faint ribs; petals 4, joined at the base. Stamens 8–16, with hairy filaments. Ovary inferior. Carpels 2–4, fused, the style long and slender, persisting on the fruit. Pollination is by insects. The fruits are dry, with 2 or 4 longitudinal wings and a hard stone with 1–3 seeds. Key Recognition Features The hanging, 4-petalled flowers and the winged fruits. Evolution and Relationships The genus is closest to Rehderodendron which differs in its 5- to 10-ribbed fruits and 5 petals. Ecology and Geography In woods and on rocky hills and plains. Four species are found in eastern North America, from West Virginia and North Carolina southwards, and 1 species is reported from eastern China. Comment The genus Halesia is named after the Rev. Stephen Hales, F.R.S. (1677–1761) an early physiologist, author of Vegetable Staticks (1727), and inventor of a bellows to pump air down to the lower decks of ships. The American species are hardy and attractive small garden trees. | 
