A deciduous shrub, ultimately 8 or 9 ft high, with erect branches; young shoots covered with a very close, fine down. Leaves obovate or wedge-shaped; 11⁄2 to 4 in. long, 3⁄4 to 2 in. wide; abruptly tapered at the apex, toothed except near the base, almost or quite glabrous except on the midrib and stalk, the latter being downy and 1⁄8 to 3⁄4 in. long. Flowers fragrant, 3⁄8 in. across, thickly set on erect, cylindrical, downy racemes 2 to 6 in. long and 3⁄4 in. wide, produced in August at the end of the current season’s shoots and in the axils of their uppermost leaves. Petals white, obovate, rounded at the apex; sepals persistent, ovate, downy; stamens and style glabrous; flower-stalk 1⁄8 in. long, downy.
Native of eastern N. America; introduced in 1731. A very handsome shrub, useful on account of its late flowering. It loves abundant moisture at the root. Propagated by layers or by separating the sucker growths at the base.
cv. ‘Paniculata’. – This form has terminal panicles (not merely clustered racemes) and is superior to the type. It is the best of all the clethras that can be grown out-of-doors, being quite hardy, a vigorous grower, and equal in flower beauty to C. tomentosa. Although described as a species – C. paniculata – by Aiton in 1789, and long grown as such or as a variety of C. alnifolia, it appears to be no more, in a botanical sense, than an extreme form of the species. However, being horticulturally distinct and almost certainly a clone, it is treated here as a cultivar. Introduced in 1770.
cv. ‘Rosea’. – Buds deep pink; expanded flowers pinkish. Leaves glossy. Introduced 1906.