Lately I've seen some Pilosocereus and a Polaskia chichipe offered in the big box retailers. I see it's planted in the ground and that you are located in California. If your location has reasonably warm winters, you might check those out. I think if you could post a close view of the cactus so that the ridge and spines are clearly seen, there are folks here that might give you a more specific suggestion. Just guessing from the water hose, it looks to be about 11-12" tall now. Would that be correct?
