Salvia muelleri 'Royal Purple Sage'
There is much debate among Salvia enthusiasts as to whether this species is the real deal or an imposter. There is certainly nothing very 'Royal Purple' about the flower colour.
Native to Mexico and thus one of the dry hardy small twiggy plants, it is certainly one of the bright sparks in an autumn garden. It is a useful filler in front of taller shrubs or half hidden with just the bright magenta purple flowers poking out from surrounding foliage.