What is a grafted cactus?

Question

What is a grafted cactus?

Answer 1

Those colorful cacti you see in nurseries from time to time are grafted. Usually a moon cactus is grafted onto some other species of columnar cactus like a cereus. Moon cactus get there color from a genetic deficiency that causes them to quit producing chlorophyll, if they aren't grafted to a green cactus they won't survive. As a rule though just about any species of cactus can be grafted to another.  

Answer 2

when you attach one to another to help it grow