Archaeophyte
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 in the New World and the Columbian Exchange began.
In some cases, introduced species, whether archaeophytes or neophytes, may have been native species before the ice ages, which extirpated vast numbers of plant species. Rhododendron ponticum is an example of a species which recolonised central and northern Europe following the Ice Ages.
Archaeophytes are often cultivated species, transported deliberately by humans, but are also often weeds of cultivation, spread accidentally with grain. Archaeophytes in the United Kingdom include sweet chestnut, wheat, field poppy, flixweed, red valerian, ground elders, soapwort, small toadflax, good king henry and cornflower.
