Over the past three centuries successive land-use decisions have led to significant changes in the composition and structure of the floristic resources at Evansburg State Park in southeastern Pennsylvania. A recent survey of the park identified 544 vascular plant species from 116 families and 337 genera across 26 distinct, yet extremely fragmented, plant communities. Slightly less than 66% of the recorded species are native to the eastern United States and only two species of concern were discovered. Forty-six species were added to the flora of Montgomery County. In addition, woody vegetation in seven mature forest types of the 16 naturally occurring community associations were sampled. A histogram of species importance across these sites reveals a trend towards increasing compositional homogeneity in forested areas. The remaining ten communities are anthropogenically influenced habitats which comprise 75% of the park's acreage, are scattered widely throughout the park, and contain a high percentage of non-native invasive species. A clear shift in the composition of the forested areas towards Acer saccharum and/or Acer rubrum dominated associations is already apparent and likely to persist given the magnitude of adverse events that continue to alter the landscape and disrupt successional processes.