B. Operette is a small shrub, approximately one-third of the size of its parent B. ‘Opera’, but retaining the latter’s long violet-lilac flowers complemented by dark-green foliage.
The cultivar was cloned from a colchicine induced tetraploid seedling of B. ‘Opera’.
Interesting the way it was cloned, but in my opinion of little garden value.
Buddleja davidii ‘Courtabud’ (selling name Operette) is a French cultivar raised by the Institut National de la Recherche Agronomique at Nancy.