Sweet Autumn-flowering Clematis (Clematis terniflora 9/1/12 D&M MD)

Looking to ID one of these plants can be problematic. I've tried to simplify it for myself.

The U.S. Integrated Taxonomic Information System (ITIS) lists C. terniflora as the accepted synonym for several other species named here:
http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=18712

THESE ARE BEST TOLD APART BY LEAF - here is the NATIVE clematis:
http://www.missouriplants.com/Whiteopp/Clematis_virginiana_page.htmlA

Our native is called "Virgin's Bower" or "Woodbine" (Clematis virginiana) which has sets of three toothed leaflets.

THE LEAF OF THE NATIVE clematis
http://www.duke.edu/~cwcook/trees/clvi.html

ICBW, but from what I gather the alien invasive, C. terniflora, can be particularly invasive in wetlands. This probably accounts for the several plants I can see blooming across the creek right now. This may also account for why I find it in areas like partially shaded roadsides where there is more rain runoff on the edges of the road.

ONLY THE LEAVES OF C. VIRGINIA (our native species) HAS LEAVES COMPOSED OF LEAFLETS OF THREE AND HAS (MORE OR LESS) TOOTHED LEAVES.

As of September 2012 C. terniflora is not on the Maryland invasive species list.
http://www.dnr.state.md.us/invasives/
it is on the Delaware invasive species list:
http://www.delawareinvasives.net/invasive_species/invasive_plants