1. Clethra Linnaeus, Sp. Pl. 1: 396. 1753; Gen. Pl. ed. 5. 188. 1754.
Sweet pepperbush [Greek klethra, alder, alluding to resemblance of leaves of certain species] Sweet pepperbush [Greek klethra, alder, alluding to resemblance of leaves of certain species]
Plants sometimes spreading by root suckers. Leaves spirally arranged, often seemingly verticillate at ends of twigs; blade not coriaceous, margins revolute, surfaces glabrous or tomentose abaxially, glabrous or with sparse, short-stellate hairs, especially when young, adaxially, venation pinnate. Inflorescences borne on new growth, racemes solitary or in clusters of 2-4, bracteate. Pedicels ridged and somewhat flattened laterally, 1-bracteate basally. Flowers fragrant; sepals imbricate in bud; petals spreading at anthesis, weakly 5-ridged, apex obtuse; filaments adnate to corolla basally, straight or S-shaped, elongate, glabrous or hairy; anthers reflexed in bud, erect at anthesis, obsagittate, base attenuate, papillose, thecae divergent distally; style straight. Capsules globose, sutures thin. Seeds strongly flattened, slightly winged; testa thin. x = 8.
Species ca. 65 (3 in the flora): s, e North America, Mexico, Central America, South America, e Asia, Atlantic Islands (Madeira).