Probably a good idea, since sources that came up appear to use a different numbering system.
I posted this question elsewhere, and was directed to a source that sells several cultivars of groundnut:
Oikos Tree Crops - groundnuts
They provide good descriptions of each cultivar, often including the Northern range. Their prices appear to be fairly reasonable.
Another poster directed me here:
Interwoven Farm - groundnuts
It appears that tubers are sold (and planted) in the Fall like garlic; really odd for a member of the bean family. Apparently they have some very rampant vines, and wide variation in tuber size & placement. I saw a reference to "containment"... which gives me sunchoke flashbacks.

The tubers are supposedly more nutritious than potatoes, it remains to be seen if the yield (and ease of harvest) would justify setting an area aside for them. If I grow these, it will be in a location other than my vegetable gardens, in case they prove to be invasive... or if, as suggested, I chose to let the tubers enlarge for a second year. Like another tuber-forming vine (
Dioscorea polystachya, Chinese yam, worth discussing in a thread of its own) the vines could be grown just for their ornamental purposes.
I'm really curious whether some of TEG's Southern members have experience with either species, since both apparently grow wild in parts of the Southern U.S..