TN native.  Not native to the east coast states, but from Pennsylvania to Alabama west to Texas to Nebraska and within.  Only an occasional find in the forest and never was a major component of any forest type.  Most outstandingly, it has huge thorns that are quite ornate and cover areas of the tree trunk to make it impenetrable.  They are wine colored turning gray with age, and can be as long as your hand and can be forked/branched.  The leaves are also unusual, in that they can be compound, partially compound and doubly compound,or doubly compound.  The seed pods are up to a foot long and wine colored/dark red.