Potato / cinnamon / yam / air/ whatever vine?

Here I am again, rehashing the vine issue.

Growing wild on our property are two vines in particular that I have
fought with myself regarding their true and common names. Ah,
those infamous interchangeable common names. Ugh!

Cinnamon vine, cinnamon yam, air potato, potato vine, the list
goes on. Spirals to the left, spirals to the right. Bears potatoes,
grows tubers, etc.

The vine on the left side of the house is very mild mannered
and insignificant, no potatoes, only underground tubers. It is a pretty
color, doesn't do much through the season, and dies back. I never see
any tubers or potatoes or seed pods above ground. The image on this
post is the 'well behaved vine' which I am confident (ha) is Cinnamon Vine

The vine on the right side of the house is always out of control, dropping
little bitty potatoes all over, then they sprout. I can easily collect a five gallon
bucket of the little potatoes each year. It is the problem child.

Dioscorea bulbifera = Air Potato? (The nasty one)
Dioscorea oppositifolia = Cinnamon Vine? (The not so nasty one)
Dioscorea villosa = Wild Yam? (Features seed pods)

Would anyone agree with the above, give or take the 'nasty' factor?

I'm not concerned about common names, but I think they are too often
confused with one another. Could someone please assist in helping me
figure out exactly what I'm growing? Yes, I've scoured the Plant Files but
find contradictory information and pictures on each one.

http://davesgarden.com/guides/pf/b/Dioscoreaceae/Dioscorea/none/cultivar/0/
Dave's Dioscorea

Many thanks!
Karen Marie

The leaves on my D. oppositifolia get to be a dark shiny green shortly after unfurling. It also gets "air potatoes" towards the end of growing season. I did see one photo in Plant Files that showed the lighter green ridged leaves that are in your picture but have never seen them on the plants I grow. My sister and my brother have the same plant (from retail sources) and they are green/shiny too.

Hope this helps you in identifying your vines.

~Sharon

D. oppositifolia will have opposite leaves...and typically when there's a species oppositifolia it is named that way because others in the genus tend to have alternate leaves, so you should be able to decide if it's that one or not based on leaf arrangement. The part about the rest of the genus having alternate leaves may not be 100% true depending on what species might have been discovered later after they already named that one, but at the very least if it has alternate leaves then you know it can't be that one, and if it has opposite leaves then it would be a strong possibility.

The leaves of your plant do not look like Dioscorea oppositifolia or D. bulbifera.

Your plant does look like Dioscorea villosa.