Physiognomy and Structure: No Data Available

Floristics: This community is strongly dominated by Phragmites australis ssp. berlandieri. Species richness in this marsh type is very low. Other species present may include Sagittaria platyphylla, Spartina alterniflora, Schoenoplectus americanus (= Scirpus americanus), Vigna luteola, Typha spp., and others. In some Louisiana examples, Colocasia esculenta, an invasive exotic, may have a strong presence.

Dynamics:  The naturalness of Phragmites australis ssp. berlandieri ("roseau cane") has been the subject of some debate, but it was at one time thought to be native in Louisiana and Texas. Accounts of the earliest settlers in Louisiana contain references to "reed marshes" in coastal . Evidence suggests that along the Gulf Coast of Louisiana and Texas, there are genotypes that differ greatly from both the native genotype found in natural, stable communities of the northern United States, as well as the one found in invasive communities of the eastern and southeastern United States. There are clear morphological differences that distinguish these taxa (and genotypes) from one another. Current research indicates that Phragmites australis ssp. berlandieri is apparently conspecific with Phragmites karka, a taxon which is also found in Australia and islands in the Pacific Ocean.

Based on observations of this nature by individuals familiar with the coastal marshes of Louisiana and Texas, apparently stable, natural communities dominated by Phragmites australis (ssp. berlandieri) are present. Evidence suggests that a new, more invasive genotype of Phragmites australis (ssp. australis, Haplotype M) was introduced to the U.S. from the Old World (Metzler and Rosza 1987, Swearingen and Saltonstall 2012) and that along the Gulf Coast of Louisiana and Texas, the genotype found in invasive communities differs from the genotype found in natural, stable communities (Hauber pers. comm. 1992, cited in Marks et al. 1994).