Salvia 'Black Knight' above Salvia leucantha
This Salvia is thought to be a hybrid of S. guaranitica x S. gesneriiflora and has been on the garden scene for a number of years.
It forms a scruffy shrub to just under two metres high with flowers so dark you have to be up close to really notice them. From a distance they appear as a dark smudge above pale green foliage. That said it is a hardy shrub which requires no special attention to do well. Perhaps with some judicious pruning in spring a well shaped shrub could be achieved.
The birds love it !