Invasive species

From Environmental Technology

A biological invasion of non-native plants is spreading into our nations' fields, pastures, forests, wetlands and waterways, natural areas, and right-of-ways. Variously referred to as exotic, nonnative, alien, noxious, or non-indigenous weeds, invasive plants impact native plant and animal communities by displacing native vegetation and disrupting habitats as they become established and spread over time.

[edit] reference

http://www.invasive.org/eastern/