BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Phragmites australis | Common Reed 



GENERAL BOTANICAL CHARACTERISTICS : 
Common reed is a tall, native, warm-season, perennial, sod-forming
grass.  The culms are erect, rigid, smooth, and hollow.  They may be
nearly 1 inch (2.5 cm) in diameter and from 6 to 13 feet (2-4 m) tall,
terminating in a 12-inch-long (30 cm) dense panicle.  Leaves arise from
the culm and are mostly 10 to 20 inches long (25-50 cm) and 0.4 to 2
inches (1-5 cm) wide [13,14].  Common reed has an extensive rhizome
network and occasionally produces stolons as well.  Rhizome depth has
been variously reported: (1) 18 to 39 inches (40-100 cm) [19]; (2)
mostly between 4 and 12 inches (10-30 cm), but up to 39 inches (100 cm)
[11]; and (3) mostly between 8 and 39 inches (20-100 cm), but up to 78
inches (200 cm) [5].  Roots grow down to a depth of about 3.3 feet (1 m)
[5].


RAUNKIAER LIFE FORM : 
   Cryptophyte


REGENERATION PROCESSES : 
Common reed's primary mode of reproduction is vegetative.  Its extensive
rhizome network is responsible for the maintenance and expansion of
existing stands.  Annual rhizome lateral spread averaged 16 inches (40
cm) in common reed stands in Wisconsin [6].  In Europe, lateral rhizome
spread has been as great as 3.3 to 6.6 feet (1-2 m) per year [20].
Stolons, which may grow up to 4.25 inches (10.8 cm) per day, are
produced in young stands or over open water and further aid in rapid
stand expansion [5,39].  

Common reed is a relatively good seed producer.  The seeds are dispersed
by wind and water and become a part of the marsh seed bank.  Seed
banking can be important in establishing new plants in vegetation-free
areas following marsh drawdown.  However, seeds of common reed are much
less abundant in the marsh seed bank that are seeds of other marsh
emergents such as cattails (Typha spp.) and bulrushes (Scirpus spp.).
Natural germination of common reed is uncommon, and successful seedling
establishment is rare [39,41].


SITE CHARACTERISTICS : 
Common reed grows on level ground in freshwater marshes, oxbow lakes,
swales, and backwater areas of river and streams.  It also grows around
springs and along pond and lake margins, streambanks, and irrigation
ditches [16,28,42].  It does not grow in permanently standing water but
rather is found on sites with high water tables or sites that are
seasonally flooded with not more than 20 inches (50 cm) of water
[3,31,39].

Soil:  Common reed grows on most soil textures from fine clays to sandy
loams and is somewhat tolerant of saline or alkaline conditions [16].
In southern Manitoba, it grows on soils with a pH ranging from 6.4 to
8.1 [39].

Associated species:  Common reed typically grows in closed, monodominant
stands but is sometimes associated with cattail, bulrush, and arrowhead
(Sagittaria spp.) in wetter habitats, and with white-top grass
(Scholochloa festucacea), thistle (Circium spp.), sedge (Carex spp.),
dock (Rumex spp.), northern reedgrass (Calamagrostis inexpansa), reed
canarygrass (Phalaris arundinacea), and American mannagrass (Glyceria
grandis) in drier habitats [16,31].


SUCCESSIONAL STATUS : 
Common reed is an aggressive competitor.  Once established it tends to
outcompete and eliminate marsh species with similar habitat requirements
to form large, unbroken, climax stands [5,8,49].

Common reed has replaced brackish water species in some coastal wetlands
where the installation of tidal gates has resulted in decreased water
salinity [9].


SEASONAL DEVELOPMENT : 
Common reed is a warm-season grass that begins growth in the late spring
usually after the last frost.  Shoots emerge in late May in southern
Manitoba [43], in April or May in Connecticut [18], in February in the
Southeast [28], and from April to June in Utah [5].  The period of shoot
emergence may last from 1 to 3 months [5].  Large buds formed the
previous fall are the first to emerge, with smaller buds emerging later
[5].  The shoots are sensitive to frost.  If killed by frost, one to
three side shoots develop from the side of the frosted shoot [18].
Spring-formed buds are small and remain dormant below the soil surface,
ready to emerge as a replacement crop following disturbance [5].

Following emergence, stems grow rapidly (up to 1.6 inches (4 cm) per
day).  In southern Manitoba stems attain their maximum height by the end
of July and maximum biomass by mid-August [43].  The foliage stays green
until frost in the fall, and thereafter becomes brittle and turns a pale
yellow.  Stems remain standing throughout the winter [5].

Time of flowering has been reported as follows:

Colorado - July through September [7]
North Dakota - August and September [7]
Utah - mid-July through August [5]
Wyoming - July through September [7]
Great Plains - June to October, mostly July to September [14]
New England - mid-August to late September [38]

Related categories for Species: Phragmites australis | Common Reed