This genus is composed mostly of American plants, and succeeds well when transplanted to the shrubbery.

Clethra alnifolia. - Alder-leaved Clethra. - A shrub, from two to eight feet high, showing a long spike of white fragrant flowers, towards the end of summer. It is generally found abundantly in wet, boggy places, and by the side of sluggish streams. Emerson says : "This beautiful plant may be easily cultivated, and is much improved by cultivation, the spikes being increased in length, and in the size of the flowers. It grows readily in any garden soil, and may be propagated by layers or cuttings."