adventive

Etymology
Borrowed from, from.

Adjective

 * 1) Accidental.
 * 2) Adventitious.
 * 3)  Of a plant that is not native, but was introduced by humans to a place and has since become naturalized.
 * 1)  Of a plant that is not native, but was introduced by humans to a place and has since become naturalized.

Noun

 * 1) A non-native plant that has become naturalized.