The plant is called butterfly bush because the plant attracts many butterflies, another name is called because the autumn lilac inflorescence that of the lilacs appear. The plant flowers with elongated flowers from July to September, the flowers are purple, pink, white or yellow - white and purple are most common variant. Most butterfly bushes are deciduous but there are also evergreen species, the shrub is about three meters high.
The name is derived from Buddleja English botanist Adam Buddle, adding davidii refers to the Frenchman Father Armand David. The plant probably originated in China, now there are over one hundred known species, the winter evergreen that blooms with fragrant B. globosa yellow 'spheres' and graceful B. alternifolia with lilac bloom briefly on the hanging branches now appear more often in our gardens.
Source: http://nl.wikipedia.org/wiki/Vlinderstruik
See also: International Flower Delivery, Florist