There is an interesting USGS fact sheet on RES for native locations and such. They just describe the interaction with PS, ending in favor of the RES.
http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=390

I have been looking to see if they will live in the Albany NY area. Looks like they can live quite a bit farther north than here, so I think they should be good. Now to find a source for them.