PHRAGMITES AUSTRALIS

TAXONOMY AND NOMENCLATURE

Phragmites australis is commonly known as common reed from the grass family.It's recent synonym is known as Phragmites communis  and its common names include Seagrass,tassel weed,reeds,sea pink and grasses.

  

Source-http://snyder-grant.org

CLASSIFICATION
 KingdomPlantae 
 SubkingdomTracheobionta 
 DivisionMagnoliophyta 
 ClassLiliopsida 
 SubclassCommelinidae 
 OrderCyperales 
 FamilyPoaceae(Grass family) 
 GenusPhragmites-Reed 
 Species Phragmites australis(Common reed)

MORPHOLOGY

 Common reed is a robust perennial grass that may reach 20 feet (6 m) tall. It's maximum height is not typically reached until plants are 5 to 8 years old. Common reed spreads by clonal growth via stolons and rhizomes, and produces dense stands.  Rhizomes typically outlive aboveground shoots. Stolons are most typical during times of low water and reach lengths of up to 43 feet (13 m).Common reed produces stout, erect, hollow aerial stems . Stems are usually leafy, persistent, and without branches. At the base, stem thickness measures 5 to 15 mm. Leaves are aligned on one side of the stem, flat at maturity, and measure 4 to 20 inches (10-60 cm) long and 0.4 to 2 inches (1-6 cm) wide. Leaf margins are somewhat rough , and leaves are generally deciduous. Common reed flowers occur in a large, feathery, 6- to 20-inch (15-50 cm) long panicle. The panicle has many branches and is densely flowered . Panicles are up to 8 inches (20 cm) wide after anthesis. Spikelets contain 1 to 10 florets. Floret size decreases from the base of the panicle upward. Lower florets are staminate or sterile and without awns. Upper florets are pistillate or perfect with awns.It's seeds are small, measuring up to 1.5 mm long . Common reed seeds collected from a salt marsh near the mouth of Delaware Bay had an average air-dry mass of 125.2 µg. 


ECOLOGY

Common reed is widespread in both estuarine intertidal and palustrine persistent emergent wetlands . It often forms monotypic stands , as other species are excluded by persistent shading and extensive utilization of space by common reed .Although common reed stands are often monotypic, adjacent wetter and drier sites may be occupied by more flood-tolerant and less flood-tolerant species, respectively. Dominant vegetation within a wetland or riparian site is often determined by water levels and flood tolerances, and so it often fluctuates with water table changes.Warm temperatures, high light conditions, and low to moderate salinity levels on moist but not flooded sites are most conducive to successful common reed seed germination.


DISTRIBUTION

Common reed is one of the most widely distributed flowering plants . It occurs on every continent except Antarctica  and is cosmopolitan in temperate zones.Phragmites is present in the Pacific and Gulf states but is not regarded as a problem in most of these areas. In Europe, Phragmites is common and encouraged to grow in many places but has been declining in many areas, particularly in eastern Europe (ISSG,2006).

The blue dots show distribution of Phragmites australis  in the UK
Source-http://www.marlin.ac.uk/images/distribution_maps/ukphraus.jpg


REPRODUCTION

Common reed reproduces sexually from seed and vegetatively from stolons and rhizomes.Local spread of common reed is predominantly through vegetative growth and regeneration, while establishment of new populations occurs through dispersal of seeds, rhizomes, and sod fragments


PHYTOREMEDIATION PROPERTIES

Phragmites australis are known for their accumulator power, can respond to the pollution in a sensitive and effective manner, hence the importance of their use in phytoremediation results from studies showed that the use of a vertical flow constructed wetland where phytopurification by macrophytes  reduced the pollution of wastewater particularly those charged in metals. hence strong purifying/accumulator power of Phragmites australis roots, particularly for trace elements. This hyper accumulation is probably the cause of their high tolerance to high levels of pollution. (Kleche et al.,2013)

SPECIES SIMILARITIES

    Arundo donax, Neyraudia reynaudiana, Spartina cynosuroides
      Arundo donax
       Neyraudia reynaudiana
      Spartina cynosuroides
REFERENCES

  1. Kleche, M., Berrebbah, H., Grara, N., Bensoltane, S., Djekoun, M., & Djebar, M. R. Phytoremediation using Phragmites australis roots of polluted water with metallic trace elements (MTE).
  2. www.fs.fed.com.2007.Phragmites australis.Available on:http://www.fs.fed.us/database/feis/plants/graminoid/phraus/all.html .Accessed:25th July 2014.
  3. www.issg.org.2006.Phragmites australis.Available on:http://www.issg.org/database/species/ecology.asp?fr=1&si=301.Accessed:25th July 2014.
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