The 'butterfly bush' Buddleja davidii is a shrub native to the mountains of China. It is widely planted for its showy sweet-smelling flowers.
Buddleia provides conservationists with a bit of quandary. It is very attractive to insects, especially butterflies, but has become invasive in parts of North America and Europe. It doesn't appear to be problematic in Scotland, though it is becoming more frequent in milder areas of UK, such as South-West England and Wales.