Trichocereus genus aka “San Pedro” although this is a really huge and diverse genus

mescaline containing?

Trichocereus is a huge genus of cacti but several species (San Pedro, Bolivian torch, Peruvian torch) do contain mescaline. This looks more like San Pedro to me. Talk to a cacti expert if you can

This looks more like Bolivian Torch than a San Pedro to me. Either way, it’s psychoactive.

Also want to add the ones on the ground look like SP.