This one has stumped the Oklahoma U. Dept of Botany and many others, hope someone out there can help. Got this plant in a mixed succulent garden about 18 months ago. It only had stacks of long, tapering, green leaves around the base then, but produced the stalk & top growth quickly last summer, then stopped growing, never flowered. Cutting a leaf across shows the inside to be solid grainy green gel. The foliage grows in 4 stacks, the stacks facing the 4 compass points, with each new leaf in the stack resting on the one below it. I've spent lots of time looking on the web for anything like this, found one with similar base but not the top stalk which was marked "crassula". Any help would be greatly appreciated. First phot shows the overall plant, second one the leaf attachment. I'm calling this one "Triffid" after the scifi book & movie about plants from outer space!