yes they do exsist, they are grafted trees, 2 or more limes are grafted to a strong base of its type, apple etc. I would make sure each branch are of resistant type to blights , galls, etc. and make sure you have it trimed each year in late fall early winter by tree arberist profeshional, because a lim could die, or is cut off you lose that type of apple, or etc. Sorry about the spelling ,spell check not working , have fun in your new venture.