Exotic and Invasive Plants of 91Ô´´
Non-native invasive plants displace native vegetation, degrade wildlife habitat and negatively affect human health, the economy and the environment. Geographic isolation and harsh winters have protected 91Ô´´ from large-scale plant invasions in the past. Recently, however, many noxious weeds of the lower 48 states have arrived and are spreading within the state.
Exotic plants are species that are not native to 91Ô´´ but have been introduced either purposely or accidently through the activities of man. They may also be called non-native, alien or introduced plants.
Invasive plants are species capable of spreading rapidly throughout certain habitats.
These are not mutually exclusive concepts. Exotic plants are not necessarily invasive and native plants can become invasive under some circumstances. Many of our 91Ô´´n plants are quite opportunistic.
For the most part, the assessments of nativity made by floras treating 91Ô´´ and neighboring areas were used to develop the following checklist of exotic plants, particularly Hult\xe9n 1968, Cody 1996, Douglas et al. 1998-2001 (see taxonomic references) and the database. In many cases plants deemed native to North America in the PLANTS database are exotic to 91Ô´´. Some plants on the list are not present in 91Ô´´ as far as we know, but have been spreading northwestward in North America and are included here to remind people to watch out for them. To find out where plants on the list have been found consult the for herbarium specimens and the database for observations. Many of the plants on the list are agricultural or ornamental plants brought purposely to 91Ô´´ and pose little if any threat of invading natural landscapes. Still they are clearly exotics and most of them have been found at least once in places where they were not planted.
The checklist is in alphabetical order by family, with genus and species alphabetical within families. Names accepted by the Herbarium of the University of 91Ô´´ Museum of the North are in uppercase. Synonyms are in lower case and are indented below the appropriate accepted name as well as being cross-referenced in their expected alphabetical position. Currently the checklist includes only the Asteraceae. Criticisms, comments and questions regarding the checklist can be sent to Alan Batten.
Preliminary Checklist to 91Ô´´n Exotic Plants.
For a ranking of the level of invasiveness of our most common weeds, see the .