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 by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are new biota to their environment in terms of established biological network relationships. Neobiota can further be divided into neozoa and neophyta (plants).
Hedera, commonly called ivy, is a genus of 12–15 species of evergreen climbing or ground-creeping woody plants in the family Araliaceae, native to Western Europe, Central Europe, Southern Europe, Macaronesia, northwestern Africa and across central-southern Asia east to Japan and Taiwan. Several species are cultivated as climbing ornamentals, and the name ivy especially denotes common ivy, known in North America as "English ivy", which is frequently planted to clothe brick walls.
The genus Tamarix is composed of about 50–60 species of flowering plants in the family Tamaricaceae, native to drier areas of Eurasia and Africa. The generic name originated in Latin and may refer to the Tamaris River in Hispania Tarraconensis (Spain).
The stone pine, botanical name Pinus pinea, also known as the Italian stone pine, Mediterranean stone pine, umbrella pine and parasol pine, is a tree from the pine family (Pinaceae). The tree is native to the Mediterranean region, occurring in Southern Europe and the Levant. The species was introduced into North Africa millennia ago, and is also naturalized in the Canary Islands, South Africa and New South Wales.
Impatiens glandulifera, Himalayan balsam, is a large annual plant native to the Himalayas. Via human introduction it is now present across much of the Northern Hemisphere and is considered an invasive species in many areas. Uprooting or cutting the plants is an effective means of control.
Cenchrus setaceus, commonly known as crimson fountaingrass, is a C4 perennial bunch grass that is native to open, scrubby habitats in East Africa, tropical Africa, the Middle East and south-western Asia. It has been introduced to many parts of the world as an ornamental plant, and has become an invasive species in some of them. It is drought-tolerant, grows fast, reaches 3 feet in height, and has many purple, plumose flower spikes.
A synanthrope is an organism that evolved to live near humans and benefit from human settlements and their environmental modifications. The term includes many animals and plants regarded as pests or weeds, but does not include domesticated species. Common synanthrope habitats include houses, sheds and barns, non-building structures, gardens, parks, farms, road verges and rubbish dumps.
Naturalisation is the ecological phenomenon through which a species, taxon, or population of exotic origin integrates into a given ecosystem, becoming capable of reproducing and growing in it, and proceeds to disseminate spontaneously. In some instances, the presence of a species in a given ecosystem is so ancient that it cannot be presupposed whether it is native or introduced.
The need for a clearly defined and consistent invasion biology terminology has been acknowledged by many sources. Invasive species, or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats. Invasion biology is the study of these organisms and the processes of species invasion.
Lathyrus aphaca, known as the yellow pea or yellow vetchling, is an annual species in the family Fabaceae with yellow flowers and solitary, pea-like fruits. It originated in the Middle East and has spread throughout Europe and beyond as a weed of cultivated fields and roadsides. The fruits are eaten as a supplement to diets in some parts of South Asia but are narcotic and potentially toxic in large quantities.
In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution during history. The term is equivalent to the concept of indigenous or autochthonous species.
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.
Lantana camara is a species of flowering plant in the verbena family (Verbenaceae), native to the American tropics. It is a very adaptable species, which can inhabit a wide variety of ecosystems; once it has been introduced into a habitat it spreads rapidly; between 45ºN and 45ºS and less than 1,400 metres in altitude.
Amorpha fruticosa is a species of flowering plant in the legume family Fabaceae, known by several common names, including desert false indigo, false indigo-bush, and bastard indigobush. It is native to North America.
Andropogon virginicus is a species of grass known by several common names, including broomsedge bluestem, yellowsedge bluestem and whiskey grass. It is native to the southeastern United States and as far north as the Great Lakes. It is known as an introduced species in California and Hawaii, where it is weedy.
In botany, a neophyte is a plant species which is not native to a geographical region and was introduced in recent history. Non-native plants that are long-established in an area are called archaeophytes. In Britain, neophytes are defined more specifically as plant species that were introduced after 1492, when Christopher Columbus arrived in the New World and the Columbian Exchange began.
Centaurea macrocephala is a species of flowering plant in the family Asteraceae, and a member of the thistle tribe, Cardueae (Cynareae). It has many common names, including bighead knapweed, big yellow centaurea, lemon fluff, yellow bachelor's button, yellow hardhat, and Armenian basketflower.
Garden waste, or green waste dumping is the act of discarding or depositing garden waste somewhere it does not belong.
Hemerochory, or anthropochory, is the distribution of cultivated plants or their seeds and cuttings, consciously or unconsciously, by humans into an area that they could not colonize through their natural mechanisms of spread, but are able to maintain themselves without specific human help in their new habitat.
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 and are generally not well established, in contrast to the native species. These plants can arrive by natural means or by human intervention.
