My sister has had this unusual cactus in her living-room in Minneapolis for many years. It only blooms every 3rd year or so. It would be interesting to learn more aabout it. Many thanks!
It isn't actually a cactus, but rather a general succulent. Looks to be very well kept. Does this particular one stink much when it blooms?
Yup, I agree w/ that ID, exactly.
If you'd like to see more of these kinds of plants, pls. search for Stapeliad, Orchids of the Succulent World, &/or Dr. Jerry Barad, a succulent collector who has specialized in this family of plants for decades.