Grape-leaf Wood Rose

I've read the additional comments and I will simply say that I am VERY familiar with the species posted and I am 'quite' sure of the ID...otherwise I wouldn't state as much...I don't 'guess' at ID's...

Should anyone have any rare Convolvulaceae species to trade , I can supply fresh seeds of Merremia vitifolia, you can grow them and see for yourself how well they match the photo...

Take a look at the parts in the link here and see if they look like they're in the 'wrong Family'...
http://davesgarden.com/guides/pf/showima...

Yes Viv, I noticed that, and that's why I'm not sure of the species, but in my opinion, this flower still looks more like Nicotiana than Merremia. If not, it is really very tricky, this one!

Hi Emilie! If you look at the third image you can see the hairy stem and leaf of this plant

You are right, Viv, the flowers are different. They are definitely not Convolvulaceae, but Solanaceae. My guess would be Nicotiana alata.

Thank you again Ron!

The flower shape can sometimes vary...

My assessment is Merremia vitifolia...