I just collected seeds from a neighbor's Clematis and thought I had IDed it as Clematis terniflora. The seeds look just like the pictures in the Database here, for one thing. But then I was looking up Clematis virginiana because it was mentioned to me, and darn if the two don't look extremely similar! Virginiana is also called Woodbine (and some other colorful names) but both of them have the common name of Virgin's Bower. Not that that's very significant, but they also both have small, fragrant, white flowers that look very much alike in the pictures.

I guess my question is, are these really two different plants that are just very similar looking? Or are they really the same plant and I am lost in the nomenclature labyrinth once again?

Further info has it that they are two different plants and easily confused, and that the terniflora is an invasive non-native (Missouri Botanical Garden info.)

So, I don't know which I have yet.

I think you'll have better luck getting a response if you ask in the Clematis Forum.

http://garden.org/forums/view/...

I have clematis with small white flowers growing wild on my property, and since I have lots of invasives (oriental bittersweet, buckthorn, Berberis AKA barberry, etc) I was worried that I had C. terniflora. So I did some research as to how to differentiate. The easiest way for me is that the leaves look quite different.
Here's a link to C. viriginiana: http://www.carolinanature.com/...
Leaves are 3 parts with large-toothed edges

Here's C. terniflora: http://www.finegardening.com/s...
Leaves also have 3 parts, but are more rounded with smooth (botanists call this entire) edges.