An archaeophyte is a plant species which is non-native to a geographical region, but which was an introduced species in `ancient` times, rather than being a modern introduction. Those arriving after are called neophytes. In Britain, archaeophytes are considered to be those species first introduced prior to 1492, when Christopher Columbus arrived.....
an non-native plant that has been present in a geographic area for some time; cf. neophyte.
archaeophyte A plant that existed in prehistoric times.