Range extensions to Butler County (Albizia julibrissin Durazz., Maclura pomifera (Raf.) C.K. Schneid., and Magnolia kobus DC.), Mercer County (Bellis perennis L.), Venango County (Lespedeza cuneata (Dum. Cours.) G. Don), and both Allegheny and Lawrence Counties (Arundinaria gigantea (Walter) Muhl.) are reported. All species are nonnative to Pennsylvania, and L. cuneata and A. julibrissin are considered invasive species in the commonwealth. The occurrence of M. kobus from a wet lowland forest in Butler County represents the first naturalized report of the species from the western half of the commonwealth. The reports of A. gigantea from Allegheny and Lawrence Counties are notable because they represent the second known occurrences of naturalized populations in Pennsylvania.