The 'butterfly bush' hardly needs introduction, although perhaps the spelling does; Buddleia is strictly incorrect. By far the best known species is B. davidii, widely grown, with arching stems and masses of flowers in late summer, in colours ranging from white to the deepest purples, almost black. There are other species, mainly with silvery foliage and purple flowers, but also one from South America with balls of bright orange flowers.
Buddleja davidii 'Nanho White' is a compact but fast-growing form with panicles of fragrant, white flowers. It is much smaller than most varieties.