[kahljorn]

both of them have mescaline. If you can go into a desert and find buttons by all means.. but you can also find san pedro just about anywhere since it is used as a landscaping plant (although there might not be a lot of cactus where you live), along with a lot of other cactii which have mescaline in them. Depending on who you ask san pedro has a similar/more/slightly less mescaline content than peyote, and it grows huge very fast, so its usually better :O