X Alworthia, Hybrid Aloe 'Black Gem'

This is fairly common garden cultivar, but I am unsure what its origins are. I have found one Aloe clone that is a cross-generic hybrid ...Read Morebetween Haworthia cymbiformis and Aloe speciosa. This plant looks very little like Aloe speciosa but it is a low-growing, prolifically offsetting plant about the right size for Haworthia cymbiformis... but no idea if that is what it really is. All photos I find of this plant are obviously of the same hybrid, a bright green, short, suckering aloe with triangular, thick leaves and a tendency to fade to black near the leaf tips, particularly in hot summer. Looks like it should be related to the Walmsley hybrids as it looks similar though a bit beefier. Supposedly a fairly cold-hardy hybrid.