Generally, the term weed is used to describe any plant that is unwanted and grows or spreads aggressively. The term exotic weed describes an invasive, unwanted non-native plant. Terms such as invasive weed or noxious weed are used somewhat interchangeably to refer to weeds that infest large areas or cause economic and ecological damage to an area.
In Indiana certain weeds have been designated "detrimental plants" and this term has legal ramifications. In residential areas only this, includes noxious weeds and rank vegetation, and in all areas the official list includes:
- Canada thistle
- Johnson grass
- Columbus grass
- Bur Cucumber
- Shattercane
