The species may be evergreen or deciduous, and all bear flowers in clusters (inflorescences), which correspond to racemes or panicles.

The flowers are quite small, white or pinkish, and each bear five free petals, numerous stamens, and a three-chambered seed capsule.

The leaves, simple, ovate, and alternate or opposite, bear characteristic stellate hairs.

[7] Clethra species are native to a variety of habitats, including swamps, woodland, and rocky sites[8] from temperate to tropical climates in eastern and southeastern Asia, Malesia, North and South America, and one species (C. arborea) on the island of Madeira.

[2] Several fossil fruits and seeds of †Clethra cimbrica have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.