An important concern of natural areas management is preserving rare taxa in the face of increasingly pervasive plant invasions. This is one study in an ongoing long-term botanical analysis of Big Everidge Hollow, a watershed containing old-growth forest within the Lilley Cornett Woods Appalachian Research Station on the Cumberland Plateau of eastern Kentucky. We report 23 new records from the site representing an array of life histories. Many of these species are scarce and difficult to identify; however, we also detected several non-native invasive species moving into the study site, which had previously been completely free of these species. The appearance of exotic species may have been facilitated by a recent wildfire that occurred in one portion of the watershed. This site remains one of the best examples of old-growth mixed mesophytic forest, and in our view, this nascent invasion poses a significant threat to the site's biological integrity.