Genus containing roughly 138 hardy, deciduous or semi-evergreen shrubs typically grown for their attractive foliage and dense blooms. Originating from rocky, thicket and woodland environments in Northern temperate climates across Eurasia and North America. Some species have particularly nice foliage which is toothed or lobed dependent on species. Flowers are produced in dense clusters on both branched and unbranched stem structures. These are small, measuring around 0.5-1cm wide and cup-shaped, with some species appearing fluffy from many longer stamens. Usual flowers colours are white, red-purple, yellow or pink.