Persicaria perfoliata (Mile-a-Minute Weed), an invasive vine, forms monocultural patches of various sizes within infested landscapes among patches also containing other plants. We compared the species composition of P. perfoliata-dominated patches and adjacent nondominated patches in 2 topographically homogeneous sites using 20 paired plots, nonmetric multidimensional scaling, multi-response permutation procedure, and indicator species analyses. Richness and diversity were lower in the P. perfoliata-dominated patches but both patch types had uncommon native plants present. The patch types differed significantly in composition, and the nondominated patches were dominated by another nonnative invader, Microstegium vimineum (Japanese Stiltgrass), or a native weed, Ambrosia artemisiifolia (Common Ragweed). Documenting potentially interacting native and exotic species within an invaded landscape will help predict likely restoration success in response to targeted nonnative-invasive plant removal. [ABSTRACT FROM AUTHOR]