Pachypodium lamerei & geayi , listed as a zone 9 at 32F.
I had some seedlings down in the low 20's this winter, ( not by choice, but that is a long and painfull story) as a result, these and my aloes picked up some red discoloration but have since outgrown it. They seem to be a little more hardy than what's listed.
Prefers desert conditions, drought & heat tolerant.
and really, really sharp pointy things all over it
