Phragmites Diagnostic Service
Phragmites australis, or common reed, is a wetland plant species found
in every U.S. state.
It can grow up to 6 meters high in dense stands and
is long-lived. Phragmites is capable of reproduction by seeds, but
primarily does so asexually by means of rhizomes. Recent research has now
shown that native and
introduced genotypes of this species currently exist in North America.
Phragmites as a problem:
The species is invasive particularly in the eastern states
along the Atlantic Coast and increasingly across much of the Midwest and in
parts of the Pacific Northwest.
Trin. ex Steudel (Poaceae)
Phragmites australis (Fig. 1), is widely distributed, ranging all
Asia, Africa, America and Australia, however, the origin of the species is
the status of the plant as native to North America or introduced has
dispute but new work has demonstrated the existence of native and
genotypes of P. australis
Native and Introduced Phragmites
australis is a
clonal grass species with woody hollow culms which can grow up to six meters in
height. Leaves are lanceolate, often 20-40 cm long and 1-4 cm wide. Flowers
develop by mid summer and are arranged in tawny spikelets with many tufts of
silky hair. P. australis is wind-pollinated but self-incompatible.
Seed set is highly variable and occurs through fall and winter and may be
important in colonization of new areas. Germination occurs in spring on exposed
moist soils. Vegetative spread by below-ground rhizomes can result in dense
clones with up to 200 stems/m2.
Distribution and Spread:
is most abundant along the Atlantic Coast and in freshwater and brackish
tidal wetlands of the northeastern United States as far south as North Carolina.
It occurs in all eastern states and populations are expanding, particularly in
the Midwest. At present, P. australis occurs throughout the entire
United States (except Alaska and Hawaii) and southern Canada.