Orobanche spp.
Broomrapes
Photo by USDA

alien species - Any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem. [from Executive Order 13112 on Invasive Species]

endangered species - A species under threat of imminent extinction.

exotic species -

extinct  -  The complete global disappearance of a species from existence. [U.S. Fish & Wildlife Service]

extirpate - The local disappearance of a species, as opposed to extinction, which is global disappearance. [U.S. Fish & Wildlife Service]

indigenous species - See "native species."

invasive species - An alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health. [from Executive Order 13112 on Invasive Species]

introduced species - Species whose existence in a given region is due to human action or activity;  this activity has led to its dispersal across natural geographic barriers, and/or has produced conditions favorable to its growth and spread.

native species - With respect to a particular ecosystem, a species that, other than as a result of an introduction, historically occurred or currently occurs in that ecosystem. [from Executive Order 13112 on Invasive Species]

non-indigenous species - See "alien species."

non-native species - See "alien species."

threatened species - Any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. [Endangered Species Act of 1973]

vector - A mechanism of transmission from one host to another.  In terms of invasive species, a vector is a path, or method, of invasion.  For example, a major vector in Zebra mussel invasion is ballast water; the Zebra mussels travel from their native waters into new regions when ballast water collected in their native ranges is discharged into non-native waters.