The following narrative s
excerpted from http://www.invasiveplants.net/phragmites/Default.htm
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.
Taxonomy:
Phragmites australis (Cav.) Trin. ex
Steudel (Poaceae)
Origin:
Phragmites australis (Fig. 1),
is widely distributed, ranging all over Europe,
Asia, Africa, America and Australia, however, the origin of the species is
unclear.
Until recently the status of the
plant as native to North America or introduced has been in dispute but new work
has demonstrated the existence of native and introduced genotypes of P.
australis
Ecology:
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:
P. australis 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.
The
following line drawings are from this link: http://plants.usda.gov/cgi_bin/topics.cgi?earl=plant_profile.cgi&symbol=PHAU7
– additional information is available there on Phragmites
