Invasive Plant Definitions: Native, Invasive, Aggressive and Non-native

Different industries, agencies, and individuals have a shared passion for invasive species control, but may use different terms for the same category of plants. Below are the terms the Missouri Invasive Plant Council (MoIP) uses in internal and external communications, including throughout this website.

Definitions

We are providing these definitions here for new MoIP members, associates, and visitors to get on the same page regarding how we talk about invasive plants at our meetings and on our website.

Native:

Native plants originally occur within a region as the result of natural processes and are adapted to local climate and soils. They have co-evolved with native insects and wildlife and are critical to ecosystem functions. For MoIP’s purposes, native plants are those species present prior to wide-spread European settlement. (Modified from GrowNative.org.)

Non-native:

Non-native plants are those introduced (intentionally or accidentally) to a new place or new type of habitat. Historically, most of these introductions have resulted from human activities. Since they did not evolve locally over thousands of years, their presence can often have negative impacts on endemic ecosystems. The words “exotic,” “alien,” and “introduced” are synonyms for “non-native.” Note: not all non-native plants are invasive and these generally are not the focus of MoIP’s attention.

Aggressive:

Aggressive plants are species that, usually because of human-caused disturbances, spread rapidly and can outcompete other plant species. Aggressive plants can be native or non-native, and they may be aggressive in some situations, but not others.

Invasive:

An invasive plant species is an aggressive, non-native species whose presence causes or is likely to cause economic harm or environmental harm. These species grow and reproduce rapidly. (Modified from Invasive.org.) 

MoIP is most concerned with invasive species because of their direct negative impacts.

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For more comprehensive definitions, we recommend “Native, Invasive, and Other Plant-Related Definitions” on the U.S. Department of Agriculture website.