and probably not rubispinus at all, but just a colorful clone of rigidissimus.
This is one of my little pet peeves in the cactus world these days, the overuse of rubispinus. The epithet was originally intended for an anomalous population of rigidissimus in the Chihuahuan Desert, definitely adapted to a cold, dry winter and heavy summer rains and with some subtle but noticeable differences from the much more common Sonoran rigidissimus, which is adapted to biseasonal rains, including a very noticeable, uniform "ruby" red spine color with very little yellow. The picture at Desert Tropicals is a good one of a real rubispinus:http://www.desert-tropicals.com/Plants/ ... pinus.html
Lots of plain old regular Sonoran rigidissimus with sort of ruby colored spines are now going under the name "rubispinus" and they are most certainly not this very special form.
end of rant.