‘Black and Blue’ is a cultivar that features deep cobalt blue flowers with black calyces. Flowers appear on spikes to 15” long over a long mid-summer to fall bloom. Problems. No serious insect or disease problems. Susceptible to downy and powdery mildew. Garden Uses.
http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c834

