Palm trees in Nuthurst village, West Sussex, England 01

Adventive plants or adventitious plants are plants that have established themselves in a place that does not correspond to their area of origin due to anthropogenic influence and, therefore, are all wild species that have only been established with the help of humans, in contrast to the native species. The term "adventive" is used to describe species that are not self-sufficient, but need an episodic population assistance from their homeland. If, however, an adventive species becomes self-sustaining in its new geographic area, it is then

naturalized Naturalization (or naturalisation) is the legal act or process by which a non-citizen of a country may acquire citizenship or nationality of that country. It may be done automatically by a statute, i.e., without any effort on the part of the in ...

. The term

hemerochory Hemerochory (Ancient Greek ἥμερος, hemeros: 'tame, ennobled, cultivated, cultivated' and Greek χωρίς choris: separate, isolated) is the distribution of cultivated plants or their seeds and cuttings, consciously or unconsciously, by hu ...

is sometimes used synonymously with this one, but is often restricted to species that were unintentionally brought into the area and then naturalized, sometimes also for species that have firmly established themselves in their new habitat.

Categorization

Depending on the question and perspective, adventitious plants are divided into different subcategories:

Classification according to establishment history

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. The cut-off date is usua ...

s were introduced before 1492 * Neophytes were introduced or immigrated after 1492. The year 1492 is a conventionally chosen reference point. With the "discovery" of America and the

age of discovery The Age of Discovery (or the Age of Exploration), also known as the early modern period, was a period largely overlapping with the Age of Sail, approximately from the 15th century to the 17th century in European history, during which seafarin ...

and

colonialism Colonialism is a practice or policy of control by one people or power over other people or areas, often by establishing colonies and generally with the aim of economic dominance. In the process of colonisation, colonisers may impose their relig ...

alien species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

from other parts of the world came to new areas on a large scale. Most of the archaeophytes immigrated with the introduction of agriculture (in the

Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts ...

). The status of a species as an archaeophyte is usually deduced (from the location and ecology of the species) and is hardly directly detectable.

Classification according to the degree of establishment

* Agriophytes: species that have invaded natural or near-natural vegetation and could survive there without human intervention. * Epecophytes: Species that are only naturalized in vegetation units shaped by humans, such as meadows, weed flora or

ruderal A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...

vegetation, but are firmly naturalized here. * Ephemerophytes: Species that are only introduced inconsistently, that will die out of culture for a short period of time, or that would disappear again without a constant replenishment of seeds.

Classification according to immigration route

Spontaneous immigrants (sometimes referred to as "acolutophytes") immigrated on their own without direct human assistance, for example when new locations were created through culture or soil changes. Companions (sometimes also "xenophytes") were brought in through human transport. Examples would be seed companions, which were unintentionally sown due to their similarity to cultivated plant seeds, or “wool adventures”, which were dragged into the wool fleece during the transport of sheep's wool. Feral species or cultural refugees in the narrower sense are those that were originally cultivated, but later escaped from the culture and were able to spread on their own. Such descendants of original cultural clans are subject to natural evolution as they become wild and can more or less quickly differ both from the culture form itself and from the original wild clan that preceded the culture.

Habitat

Adventitious plants are often found at

freight station A goods station (also known as a goods yard or goods depot) or freight station is, in the widest sense, a railway station where, either exclusively or predominantly, goods (or freight), such as merchandise, parcels, and manufactured items, are lo ...

s, along

railway line Rail terminology is a form of technical terminology. The difference between the American term ''railroad'' and the international term ''railway'' (used by the International Union of Railways and English-speaking countries outside the United Sta ...

s and port areas as well as airports, but also on roads. Seeds of many species were accidentally imported there with the import of goods (so-called agochoria). Occasionally, seed contamination also introduces new plants that could reproduce for a short period of time (so-called speirochory). Agochory and speirochory are sub-forms of

. The seeds can also hang in wheel arches so that they can be transported and distributed along highways. The proportion of adventitious species in open ruderal corridors at such locations can exceed 30% of the flora of these locations. In natural and near-natural vegetation, adventitious plants are much rarer. Their share here is between zero and about 5%.Wilhelm Lohmeyer, Herbert Sukopp: Agriophytes in the vegetation of Central Europe. First addendum. 2001 (Braunschweiger Geobotanische Arbeit 8), pp. 179–220

References