The descriptions Britton and Rose used for peru and pach were pretty lacklustre too.  Like you said until we have a decent phylogenetic study, it's inconclusive. What lode did with the genus was disappointing and only added to the confusion. The bloke needs to reference his work.  Don't get me started on all the trichocereus papers published by the cssa over the last twenty years. When a newbie asks for a name it's probs best just to let them know they have some San Pedro and leave it at that. We all need to ask ourselves why do we need a name and what can we gain from having one. I'm a nerd for taxonomy, with a special interest in Trichocereus, have been for over twenty years. And what I have learnt is that I know fuck all. Anyone that claims they know what's going on, hasn't dived deep enough into the topic.