In its broad sense (as a monotypic genus), this species is widespread across temperate regions of the world, with a ange of reported chromosome numbers from 36 to 120 (FNA 25). [For notes on tribes, see under Arundo.] Ky. plants of Phragmites may all be the European ssp. australis. They are locally abundant in western regions of the state within disturbed wetlands and adjacent seasonally wet uplands, also frequent in patches along major highways. However, to the south of Ky. and Va., Phramites is uncommon to absent across most of the southeast, except for coastal marshes (K). The native ssp. americanus Saltonstall, P.M. Peterson & Soreng has been recently described and imay be considered a distinct species (W); it is widely distributed across cool temperate North America in fens and marshes, but generally less common and less vigorous (Saltonstall et al. 2004; and supplementary website). D. Boone (pers. comm.) has recently found ssp. americanus in e. Ind. (Randolph Co.), and it is reported from w. Ohio (Cedar Bog). The best diagnostic character for ssp. americanus is its longer ligules (1-1.7 mm versus 0.4-0.9 mm). Other differences from ssp. australis are its usually longer lower glumes (3-6.5 mm versus 2.5-5 mm) and upper glumes (5.5-11 mm versus 4.5-7.5 mm); more open inflorescence; leaves yellow-green (versus usually blue-green), the sheaths loose and soon dropped (versus tight, usually persistent); culms smooth (versus longitudinally ridged), green to maroon, at least at nodes (versus usually all green), and with black fungal spots often present at nodes and below (versus rarely present); plants often mixed with other species (versus usually in monocultures). Although no general difference in ploidy exisits, there is evidence of much difference in gene loss versus retention after initial whole genome duplication by the ancestral lineage of Phragmites (Oh et al. 2022).