Native plants are those that live or grow naturally in a particular region.

Exotic, alien, and non-native plants are plants whose presence in a given area is due to accidental or intentional introduction by humans. The majority of non-native plants are beneficial to society, including staple crops and ornamental plants.

Naturalized plants are exotic plants that reproduce consistently in their new environment and sustain populations over many life cycles without direct intervention by humans.

Invasive plants are exotic plants that produce viable offspring in large numbers and have the potential to establish and spread in natural areas. Invasive plants often have a negative effect on ecosystems and may cause economic losses or harm to human health.

A weed is any plant, native or exotic, whose presence is undesirable to people in a particular time or place.

A noxious weed is a plant that has been defined as undesirable by legal statute.