Salvia 'Black and Blue' (Salvia guaranitica) (aka Blue Anise Sage, Brazilian Sage, Sapphire Sage)
There are more varieties of salvia than you can shake a stick at and I love them all but if I could only choose one, this would be it. Salvia 'Black and Blue' is named for the color of the flowers - cobalt blue flowers that emerge from jet black calyces. These tubular flowers persist throughout the summer (plants can be sheared in mid-summer for fall bloom) and it is one of the top favorites of hummingbirds. Although the flowers are the star attraction, the foliage itself is quite nice. Light green fuzzy leaves are strongly scented with a sage-like fragrance. This salvia is considered somewhat tender but it has overwintered in my garden for the past four years. Mulch it heavily during the winter months and be sure you grow it in well-drained soil - wet feet will certainly kill it during the winter months. (Cameron at Defining Your Home, Garden & Travel advises not cutting the stems back during the winter months). It will spread but not to the point of invasiveness. Share it and enjoy!