Sweet Autumn Clematis

Sweet autumn clematis is a vigorous vine that's been planted in the South for years. Despite its attractive qualities, sweet autumn clematis has some drawbacks, namely that it's invasive.
The Florida Exotic Plant Council lists this vine as a Category II invasive species in Central and North Florida. This is defined as "Invasive exotics that have increased in abundance or frequency but have not yet altered Florida plant communities to the extent shown by Category I species. These species may become ranked Category I, if ecological damage is demonstrated." The UF/IFAS Assessment of Non-Native Plants in Florida's Natural Areas lists sweet autumn clematis as a high invasion risk, and is not recommended. UF/IFAS adheres to the most conservative recommendation.
There is a native alternative, Clematis virginiana, but it can be difficult to find. Making it even more difficult is that both the invasive and native vines are often sold under the same common name, sweet autumn clematis. One way to tell the difference is that the native clematis has serrated (jagged) leaf edges, whereas the invasive clematis has smooth leaf edges.

Clematis terniflora vine smothering a tree