Buddleja davidii Black Knight AGM, 3LBuddleia davidii Black Knight is the solution for anyone looking for a shrub with deeply coloured flowers, in this case a lovely deep, grape purple with orange centres. It is a large and vigorous shrub with arching branches holding numerous long and slender panicles of honey scented flowers throughout the summer. A recipient of the RHS AGM (Award of Garden Merit), for all round excellence in the garden.