Phragmites | |
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Phragmites australis seed head in winter | |
Scientific classification | |
Kingdom: | Plantae |
(unranked): | Angiosperms |
(unranked): | Monocots |
(unranked): | Commelinids |
Order: | Poales |
Family: | Poaceae |
Subfamily: | Arundinoideae |
Tribe: | Molinieae |
Genus: |
Phragmites Adans. |
Synonyms | |
Phragmites is a genus of four species of large perennial grasses found in wetlands throughout temperate and tropical regions of the world. The World Checklist of Selected Plant Families, maintained by Kew Garden in London, accepts the following four species:
The cosmopolitan common reed has the generally accepted botanical name Phragmites australis. (Cav.) Trin. ex Steud. About 130 other synonyms have been proposed, and some have been widely used. Examples include Phragmites communis Trin., Arundo phragmites L., and Phragmites vulgaris (Lam.) Crép. (illegitimate name).
Recent studies have characterised morphological distinctions between the introduced and native stands of Phragmites australis in North America. The Eurasian phenotype can be distinguished from the North American phenotype by its shorter ligules of up to 0.9 millimetres (0.04 in) as opposed to over 1.0 millimetre (0.04 in), shorter glumes of under 3.2 millimetres (0.13 in) against over 3.2 millimetres (0.13 in) (although there is some overlap in this character), and in culm characteristics.
In North America, the status of Phragmites australis was a source of confusion and debate. It was commonly considered an exotic species and often invasive species, introduced from Europe. However, there is evidence of the existence of Phragmites as a native plant in North America long before European colonization of the continent. It is now known that the North American native forms of P. a. subsp. americanus are markedly less vigorous than European forms. The recent marked expansion of Phragmites in North America may be due to the more vigorous, but similar-looking European subsp. australis.
Phragmites outcompetes native vegetation and lowers the local plant biodiversity. Phragmites forms dense thickets of vegetation that is unsuitable habitat for native fauna. Phragmites displaces native plants species such as wild rice, cattails, and native wetland orchids.Phragmites has a high above ground biomass that blocks light to other plants allowing areas to turn into Phragmites monoculture very quickly. Decomposing Phragmites increases the rate of marsh accretion more rapidly than would occur with native marsh vegetation.