Spotting

It's sharp-pod morning glory; Ipomoea Cordatotriloba.

http://131.230.176.4/imgs/Cusman1/r/Conv...

http://131.230.176.4/imgs/pelserpb/r/Con...

Its look different... The shade at throat..
http://www.gardenology.org/wiki/File:Ipo...

Sweet potato leaves are extremely variable...check out the link I posted with my suggestion.

Sweet potato climber's leafs are more... Palmately.
http://en.wikipedia.org/wiki/Ipomoea_mau...

I can say its might be Ipomoea arachnosperma or Ipomoea pilosa....!!

The flower looks like the sweet potatoe but the leaf and stem don't match

I agree with ceherzog's sweet potato suggestion.

Possibly Sweet Potato, Ipomea batatas?
http://www.google.com/search?q=sweet+pot...

possibly a type of morning glory?

I'm not sure of the species. The blooms look a lot like Ipomea cairica but the leaves don't match.