Clematis terniflora (SAC) is a non-native species with rounded leaves that is considered invasive in some areas of the country. Clematis virginiana, aka virgin's bower, is a native species with heavily toothed leaves. As a native, it is not technically considered an invasive species, however it does have an ability to seed itself around a bit.

Aside from the leaf distinctions, there is little to distinguish the two apart. Both are large growing, very robust vines with nearly identical fragrant, white flowers and a late summer/early fall bloom time.

I've got the native one-as a wild plant, not something I put there-clambering all over the shrubs and whatnot at my up north place. Pretty cool plant. that foreigner is quite awesome as well. I haven't seen it escape around here but it stands to reason it could be doing so.

Sue, you don't say where you are; in my cold part of the country, sweet autumn doesn't have time to ripen seeds, but starting just a bit warmer than me where there's a longer season, it can be quite a pest. I have C. virginiana that grows wild here in the flood plain along the stream that is lovely not only when it blooms, but also the fluffy white seeds that hang on for quite a while after. They do seed around some, but not enough to be a problem for me.

Here's a link to a page that has good photos to help see the differences in the leaves.

thank you nhbabs! thats very informative.

I am in Zone 4 midwest, Wisconsin

Sue, if you want to add that info to your profile so that it shows automatically by your name, here's how:

Go to Your Houzz in the upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone.

If you add info on your state or the nearest large city you will get even better information since zone only relates to average coldest winter temperatures.

Then return to the top of the page and click Done Editing.