1. Halesia J. Ellis ex L. (silverbell)

Plants shrubs or more commonly small trees. Bark gray and brown, initially with a network of shallow, longitudinal ridges (often appearing striped), on older trunks eventually flaking off in small plates. Twigs green, darkening to grayish brown or more commonly reddish brown, often with darker lenticels, shiny, pubescent with small stellate hairs when very young, becoming sparsely hairy or glabrous at maturity, the outer layer usually peeling or shredding in thin strips with age, the winter buds ovoid to ellipsoid, with several overlapping scales, the pith chambered. Petioles 10–35 mm long. Leaf blades narrowly to broadly ovate to obovate, rarely oblanceolate, rounded to broadly angled at the base, bluntly and broadly pointed to noticeably but abruptly tapered at the tip, the margins minutely toothed, the surfaces felty with minute stellate hairs when young, these shed in patches, essentially glabrous at maturity, the upper surface green, the undersurface usually pale green to grayish green. Inflorescences axillary, small clusters or short racemes of 2–6 flowers, rarely reduced to solitary flowers. Flowers epigynous, the calyces fused to the full length or the ovary, the outer surface stellate-hairy, the free portion absent or extending above the ovary as 4 small, more or less triangular lobes to 2.5 mm long, the stalk jointed at the calyx base. Corollas shallowly or deeply 4-lobed, bell-shaped, the lobes more or less ascending at maturity. Stamens 8–16. Fruits samaralike, 2.5–6.0 cm long green, turning tan to reddish brown at maturity, variously shaped, beaked at the tip, appearing somewhat flattened, 2- or 4-winged, the surface glabrous or nearly so at maturity, the middle layer more or less mealy, usually developing a hollow chamber above the seeds, indehiscent. Seeds relatively thin-walled, narrowly ellipsoid, pointed at each end. Three species, U.S., Asia.

As many as five New World species (plus one Asian taxon) have been recognized by some authors, but Fritsch and Lucas (2000) determined that only two morphologically separable species exist in North America.