Duvaliandra dioscoridis. So, this is in the same group of plants as the Stapelia plants, and I haven't found too much information on it. I will walk you through all that I know.
Duvaliandra is a monotypic genus consisting of this one species.
D. dioscoridis is endemic to the small Island of Socotra, the largest of an archipelago of four islands in the Indian Ocean, just east of the horn of Africa. It is part of the Republic of Yemen. Socotra is so remote that many of the plants on the island are unique to this location, and cannot be found elsewhere in the world. UNESCO declared Socotra a world heritage site, due to the extraordinary biodiversity. A rare succulent, indeed.
This plant is of the Arid Lands crop that Gethsemane has been selling for the past month. Bob Webb recommended it to me, so of course I picked it up. The specimen I picked had two tiny buds on its branching arm, and fortunately, one has been progressing nicely, and hopefully will bloom soon!
You can see the distal bud is starting to take off, but the proximal bud isn't doing too much. Probably gone already.