Adventive plant

Adventive plants, also known as alien plants, foreign plants or casual plants are alien plant species appearing in a place that does not correspond to their area of origin, in contrast to the native species. These plants can arrive by natural means (such as wind or animal) or by human intervention (either intentional or accidental).

Although some alien plants become naturalized, others do not become established, thereby distinguishing them from weeds or an invasive species. Many alien plants have been introduced to aesthetically improve public recreation areas or private properties, or for agricultural purposes. The term "adventive" is derived from the Latin advena, meaning a 'stranger', 'alien' or 'immigrant'.