Informative with good photos. I think you underestimate the knowledge about these plants that many people in California have. www.desert-tropicals is a reasonable source of information on the internet.
Plants cannot be identified from photos such as these. Often the flowers or fruits need to be seen.
Euphorbia tortirama might be the right name for Euphorbia tortulana, although I cannot tell from the photo. This also looks like another columnar Euphorbia.
Any article should point out the dangers in handling Euphorbias. Very real danger.
Much of the fun is the time and the effort it takes to learn about these plants. Many sold in commerce are of unreliable origin. Some euphorbias have no original known habitat.
Indeed, there is still a LOT to learn about these plants, particularly by us folks living and growing them halfway around the world from where they came. As for mentioning the dangers of Euphorbias, I have discussed that in other articles, and perhaps more articles to come, but I find the dangers are far over emphasized and that these plants are not nearly as dangerous as many claim they are. However, there also appears to be a lot of individual variation in susceptibility to the toxic affects of Euphorbias, at least topically. Some are quite irritated by the saps, while others seem unaffected. Not too many people ingest Euphorbias, or most other toxic succulents for that matter, but few would get much further than a taste as they are so irritation ingestion is probably a rarity. Still, all that is fodder for other articles. this article was simply an introduction to some of the columnar species I see all the time in botanical gardens, and an attempt to get a handle on what the are and how they do in this climate. I obviously failed to make that clear and perhaps I will rewrite the introduction in the future.