Aeonium arboreum Zwartkop Succulent Black Rose or the Black Desert Rose succulent. 

These Black Rose Succulents, which there are a few variations, has a large flattish rosette of deep purple leaves. A fast growing branching succulent plant that enjoys either sun or shade and is tolerant ( dormant ) in warm summer and dry conditions but does best in cool and dry environments in the fall and winter. Blooms in the Spring, picture of blossom intended to show example of potential. 

Plants are sold as individual rosettes, ranging in size from 4 to 6 inches in diameter, propagated from the original parent plant.