I don't remember the heritage but this one is a cross of T. pachanoi and another Trichocereus species. The munch mark was courtesy of my (then) 6 or 7 year old son wielding some unknown garden implement.
I really don't do much for it. I'll toss a handful of organic tomato ferts into the...
Nice cacti Carlton! I have an old battle scarred Trichocereus myself. It's bloomed (night bloomer!) 4 or 5 times in the 20 something years I've had it, I've attached pics of the last time it flowered, 2 years ago.