I have looked at cactiguide.com and there are lots of pic's etc but what i'm going to need is the systematic key to cereus.
My Cereus are a mess, several batches of suposedly different species that look largely the same, then there's C aethiops with bright orange spines and C jamacaru with 9 ribs, plus a Cereus/Ferocactus glaucescens that found its way into a pkt of peruvianus seed.
Although i have a 1year old "C horrispinus" that is spiraling nicely, for the moment at least, so i suppose i shouldn't complain to much.