Snail or Corkscrew...how can I tell

I would like to try a snail vine but am finding that many stores and nurseries confuse snail vine and corkscrew vine. If they are confused, how can I tell for sure I am getting a snail vine?

Buy it from Montecello, their's is the real one.

Try to go by description:
Vigna Caracalla-Corkscrew Vine is cream color with purple edges & highly fragrant.
http://davesgarden.com/pf/go/1884/index.html
Phaseolus Caracalla-Snail Vine is solid purple & has no fragrance.
http://davesgarden.com/pf/go/53274/index.html

Has anyone grown corkscrew vine? Is it easy to grow? I've seen catalogs with it and was wondering if I should try. How about starting it from seed?
Thanks,
Mara

I grow them from seed with good success. I nick and soak overnight in hottest tap water, then plant and keep bottom heat going until I get sprouts, approx 1-2 weeks. My bottom heat is 69 degrees.

Where did you get your seed from? And what sorts of growing conditions do they like? I would love to grow some this year!
-Mara

I think I saw some in the Park seed catalog & also Seedsavers. I am sure there are other places that carry them. They like sun.

Park seeds is sold out.
When comparing the seeds, there is a major difference in size and appearance. The vigna is several times the size of phaseolus and vigna is more flat and shiny.

To compare the mature plants, vigna leaves are slightly larger than phaseolus and of course the blooms are much different. Also vigna is fragrant, phaseolus is not.

I haven't grown phaseolus from seed as I have a large plant and start from cuttings.

I have about 8-9 vignas I have started from seeds and they do pretty well.
They are not large enough to bloom yet. I have 6 new seedlings emerging from 6 seeds I pre-sprouted in water and peroxide.
Jan...