Identification: Introduced Phragmites australis subsp. australis is a perennial reed that grows from elongated rhizomes or stolons; 1-6 meters tall, forms dense stands which include both live and standing dead stems from previous year’s growth (Clayton et al. 2006, Klein 2011).
Leaves and Stems:
Culms (stems) erect; hollow; reed-like; simple; 150–600 cm long; 5-15 mm thick; hollow internodes (Clayton et al. 2006, Klein 2011). Culms are tan in color; ridged or ribbed; have a rougher texture than the native common reed (Swearingen and Saltonstall 2010).
Leaves are linear to lanceolate-linear; flat; drooping; leaf-blades deciduous at the ligule; 20–60 cm long; 8–32 mm wide with pointed tips (Clayton et al. 2006, Klein 2011). Leaf blade surface smooth; cauline (Clayton et al. 2006). Leaves are blue green and usually darker than the native lineage (Swearingen and Saltonstall 2010). Each leaf consists of a blade and a loose sheath separated ciliate ligules that form minute membranous rims fringed with hairs; 0.2-0.6 mm long (Clayton et al. 2006, Klein 2011). Leaf sheaths adhere tightly to culm throughout the growing season; persistent (Swearingen and Saltonstall 2010). Leaf-blade apex attenuates; filiform (Clayton et al. 2006).
Flower-head and Flowers:
Inflorescence a panicle; bearing juvenile spikelets at emergence (Clayton et al. 2006). Panicles are oblong, purplish when young, straw colored at maturity; 15-50 cm long; 6-20 cm wide (Clayton et al. 2006, Klein 2011). Primary panicle branches divided; bearing spikelets almost to the base Clayton et al. 2006). Spikelets solitary; pedicelled (Clayton et al. 2006). Pedicels are filiform (Clayton et al. 2006). Spikelets comprising 3–11 florets; with diminished florets at the apex (Clayton et al 2006, Klein 2011). Spikelets cuneate; laterally compressed; 10–18 mm long; stalked with 6-10 mm long hairs on the stalks; breaking up at maturity (Clayton et al. 2006). Floret callus elongated; 1–1.25 mm long; bearded; obtuse. Glumes are paired; persistent; shorter than spikelets; gaping (Clayton et al. 2006). Lower glume lanceolate; 3–7 mm long; 0.5–0.6 length of upper glume; membranous; without keels; 3–5 veined. Lower glume apex acute. Upper glume lanceolate; 5–10 mm long; without keels; 3–5 veined (Clayton et al. 2006, Klein 2011). Upper glume apex acute (Clayton et al. 2006). Basal florets are sterile florets are male with palea; persist on panicle (Clayton et al. 2006). Lemma are glabrous; lanceolate; 8–15 mm long; membranous; acuminate; with somewhat in-rolled margins. Lower lemmas are unawned and upper lemmas are awned; Lemma apex acuminate (Clayton et al, 2006, Klein 2011). Palea present; with scaberulous keels (Clayton et al. 2006). Flowers typically occur in August and September and form bushy panicles that are usually purple or golden in color with 2 lodicules, 3 anthers, and a glabrous ovary (Clayton et al. 2006, Klein 2011).
Fruit is a caryopsis with an adherent pericarp (Clayton et al. 2006). Seeds are 2 to 3 mm long (Klein 2011). As seeds mature, the panicles begin to look “fluffy” due to the hairs in the spikelet on the rachilla, and they take on a grey sheen (Saltonstall 2005).
Below ground, Phragmites australis forms a dense network of roots and rhizomes which can go down up to two meters in depth to reach deep ground water (MA DCR 2002). The plant spreads horizontally by sending out underground rhizomes and over ground runners which can grow 10 or more feet in a single growing season if conditions are optimal (Swearingen and Saltonstall 2010).
Distinguishing Between Native and Non-native Phragmites australis:
Many morphological characteristics can be used to distinguish native Phragmites australis subsp. americanus from the introduced lineage Phragmites australis subsp. australis. However, there are many overlaps in characteristics making it necessary to look at multiple factors when making a determination based on morphology. The following characteristics should NOT be used to distinguish populations in southern areas (California to the Gulf of Mexico) where the Gulf coast type may be present as it is very similar in appearance to the introduced lineage (Swearingen and Saltonstall 2010).
Introduced Phragmites australis subsp. australis typically forms denser stands than the native Phragmites australis subsp. americanus, the introduced subspecies stands are also more likely to include dead stems from the previous year’s growth (MNFI 2016, Swearingen and Saltonstall 2010). Introduced Phragmites is more likely to form monocultures, outcompeting and excluding other plant species. The native Phragmites, is much less robust, typically occurring in low density stands, and is frequently found with other native plants but it can occasionally occur in very dense stands more typical of the introduced form when enriched with nutrients (MNFI 2016, Swearingen and Saltonstall 2010).
Leaves of the invasive subspecies are a bluish gray-green, while those of the native lineage are typically a lighter yellow-green (MNFI 2016, Swearingen and Saltonstall 2010). This is easiest to see when they grow side-by-side (MNFI 2016).
The leaf sheaths of the introduced Phragmites adhere more tightly to the culm and persist as long as it remains standing, whereas those of the native lineage adhere less tightly and peel back eventually dropping off the culm once the leaf dies particularly at the lower nodes exposing the stem below (MNFI 2016, Swearingen and Saltonstall 2010).
Culms and Rhizomes:
Culms of the introduced lineage are rigid and have a rougher texture than the native, which is usually smooth and shiny (MNFI 2016). Culms of the native lineage are more likely to be red, typically around the nodes and where the leaf sheaths have been lost. Whereas the culms of the non-native lineage are usually a dull tan color (MNFI 2016). However, non-native Phragmites has stolons that can grow up to 50 feet or more in a season and may be red, also a little red may occasionally be seen on the culms of the introduced lineage but it is usually limited to lower nodes, which may lead to confusion (MNFI 2016, Swearingen and Saltonstall 2010). Little black spots are sometimes found on the culms of the native lineage, which are caused by a native fungus that has not yet adapted to the introduced form (Swearingen and Saltonstall 2010). The culms of the introduced form may have a sooty like mildew but it does not have the distinctive black fungal spots (Swearingen and Saltonstall 2010). Rhizomes of the native subspecies rarely exceed 15 mm in diameter and are a darker yellow than the introduced lineage (Swearingen and Saltonstall 2010).
The ligule of the introduced lineage is typically less than 1 mm (0.4-0.9 mm) in length. Ligules of the native are more than 1 mm (1-1.7 mm) (Swearingen and Saltonstall 2010). The native Phragmites is less sturdy and therefore its ligule is more likely to shred and fray by midsummer (MNFI 2016).
For the introduced lineage, the upper glume ranges in size from 4.5-7.5 mm, with most being <6 mm and the lower glume ranges in size from 2.5-5.0 mm, most being <4 mm; the native subspecies has an upper glume ranges in size from 5.5-11.5 mm, with most being >6 mm and lower glume is ranges in size from 3.5-6.5 mm, with most being >4 mm (Swearingen and Saltonstall 2010).
Introduced Phragmites is typically found in ditches, disturbed sites, and can tolerate saline habitats. In the Great Lakes basin, it is frequently found on shorelines (MNFI 2016). The native lineage is usually found in fens, sedge meadow, river banks and shores, and the Great Lake shores (MNFI 2016).
Introduced Phragmites begins growing earlier in the season and continues later in the fall than does the native lineage (MNFI 2016).
Impact of Introduction: Phragmites australis has a high environmental impact in the Great Lakes.
In controlled experiments, the introduced and native lineages of Phragmites can hybridize, which may act as a mechanism for further decline of native Phragmites in North America where it comes in contact with introduced stands. However, no naturally hybridizing populations have been found (Meyerson et al. 2010).
Phragmites threatens the biodiversity of Michigan’s coastal and interior wetlands. It displaces native species including sedges, rushes, and cattails; and reduces wildlife habitat diversity, resulting in loss of food and shelter for native wildlife (Avers et al. 2010). Reduction and degradation of wetland wildlife habitat is due in part to Phragmites’ dense and prolific growth pattern (Swearingen and Saltonstall 2010). The introduced common reed forms impenetrable monocultures and is capable of dominating wetlands with its increased canopy height within a few years (Rudrappa 2009). Its success may also be attributed to the release of gallic acid, which is degraded by ultraviolet light to produce mesoxalic acid, effectively hitting susceptible plants and seedlings with two harmful toxins (Rudrappa 2009). Furthermore, Phragmites alters wetland hydrology through increased evaporation and trapping of sediments, causing marsh soils to dry out (Avers et al. 2010, Swearingen and Saltonstall 2010).
Phragmites australis has a moderate socio-economic impact in the Great Lakes.
Tall, dense stands of the introduced Phragmites impede shore access, as penetration of a stand of introduced Phragmites can not only be difficult but can also result in abrasions from the sharp-edged vegetation (Avers et al. 2010, USFWS 2007). Recreational value for birdwatchers, walkers, naturalists, boaters, and hunters is further diminished through reduction of native fish and wildlife populations (USFWS 2007). Such use impairment and restricted shoreline view also reduce property values (Avers et al. 2010).
In addition to economic impacts, the introduced Phragmites poses a risk to human life and property. The Michigan Department of Transportation (MDOT) considers Phragmites to be a safety hazard, as its height and dense growth may block signs and view of access roads, drives, curves, etc. (B. Batt, MDOT, pers. comm.). During its dormant season, when dry biomass is high, the introduced common reed also creates a potentially serious fire hazard to structures (Avers et al. 2010, Swearingen and Saltonstall 2010).
Phragmites australis has a moderate beneficial effect in the Great Lakes.
In Europe, Phragmites is grown commercially and used for thatching, fodder for livestock, and cellulose production (Swearingen and Saltonstall 2010). In Canada, despite its status as the nation’s “worst” invasive plant species, Phragmites is still found as an ornamental in some garden and landscape designs (MNR 2010).
Phragmites produces various potentially interesting pharmacological compounds, including polysaccharides, anthocyanins, alkaloids (DMT, dimethyltryptamine; Kiviat 2010), but to our knowledge there is no current research focus in this area.
As a wetland plant, Phragmites improves water quality by filtration and nutrient removal (Ailstock 2004). Phragmites provides food and habitat for some organisms and serves to stabilize soils against erosion. Bobolink and sparrows eat its seed, while numerous insects eat the vegetation. Moreover, many insects, birds (including yellowthroat, marsh wren, salt marsh sparrow, least bittern, red-winged blackbird, and some wading birds), and muskrats use Phragmites as shelter or nest material (Kiviat 2010).
References: (click for full references)
Ailstock, M.S. 2004. Summary of common questions concerning Phragmites
control. Available http://www.nap.usace.army.mil/Projects/LCMM/Summary%20of%20Common%20Questions%20Concerning%20Phragmites%20Control.pdf. [Accessed 7 September 2011]
Avers, B., R. Fahlsing, E. Kafcas, J. Schafer, T. Collin, L. Esman, E. Finnell, A. Lounds, R. Terry, J. Hazelman, J. Hudgins, K. Getsinger, and D. Scheun. 2014. A Guide to the Control and Management of Invasive Phragmites. Third Edition. [Booklet] Michigan Department of Environmental Quality, Lansing.
Blossey, B. 2007. Development of biological controls for Phragmites australis. Grant C-06-26. NYSDOT.
Blossey, B., M. Schwarzländer, P. Häfliger, R. Casagrande, and L. Tewksbury. 2002. 9 Common Reed. Pages 131-138. in Driesche, F.V., B. Blossey, M. Hoodle, S. Lyon, and R. Reardon (Eds.). Biological Control of Invasive Plants in the Eastern United States. United States Department of Agriculture Forest Service. Forest Health Technology Enterprise Team. Morgantown, West Virginia. FHTET-2002-04. 413 pp.
Brisson, J., E. Paradis, and M. Bellavance. 2008. Evidence of sexual reproduction in the invasive common reed (Phragmites australis subsp. australis; Poaceae) in Eastern Canada: A possible consequence of Global Warming. Rhodora 110 (942): 22-230. Available http://www.bioone.org/doi/full/10.3119/07-15.1. [Accessed 19 May 2016]
Chesier, J.C., J.D. Madsen, R.M. Wersal, P.D. Gerard, and M.E. Welch. 2012. Evaluating the Potential for Differential Susceptibility of Common Reed (Phragmites australis) Haplotypes I and M to Aquatic Herbicides. Invasive Plant Science and Management 5: 101-105.
Clayton, W.D., M.S Vorontsova K.T. Harman, and H. Williamson. 2006. GrassBase - The Online World Grass Flora. Available: http://www.kew.org/data/grasses-db.html [Accessed 18 May 2016]
Fofonoff, P.W., G.M. Ruiz, B. Steves, and J.T. Carlton. 2003. National Exotic Marine and Estuarine Species Information System. Available: http://invasions.si.edu/nemesis/. [Accessed 23 May 2016]
Getsinger, K.D., L.S. Nelson, L.A.M. Glomski, E. Kafcas, J. Schafer, S. Kogge, and M. Nurse. 2007. Control of Phragmites in a Michigan Great Lakes Marsh – Final Report. U.S. Army Engineer Research and Development Center, Vicksburg, MS, 120 pp.
Great Lakes Phragmites Collaborative. 2015. Phragmites australis (common reed). Great Lakes Commission. Available http://greatlakesphragmites.net/. [Accessed several times]
Gucker, C. L. 2008. Phragmites australis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/. [Accessed 23 May 2016]
Haslam, S. M. 1971. The development and establishment of young plants of Phragmites communis. Trin. Annals of Botany 35: 1059-1072.
Haslam, S. M. 1972. Biological flora of the British Isles: Phragmites communis. Journal of Ecology 60: 585-610.
Hazelton, E.L.G., T.J. Mozdzer, D.M. Burdick, K.M. Kettenring, and D.F. Whigham. 2014. Phragmites australis management in the United States: 40 years of methods and outcomes. AoB Plants 6: plu001.
Indiana Department of Natural Resources (IN DNR). 2005. Aquatic Invasive Species – Plants. Available: www.in.gov/dnr/files/PHRAGMITES2.pdf. [Accessed 19 May 2016]
ISSG. 2011. Phragmites australis. Global Invasive Species Database. Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG). Available at http://www.issg.org/database/species/ecology.asp?si=301&fr=1&sts. [Accessed 5 April 2011]
Kiviat, E. 2010. Phragmites Management Sourcebook for the Tidal Hudson River and Northeastern States. Hudsonia Ltd., Annandale, NY.
Klein, H. 2011.University of Alaska Anchorage: Alaska Center for Conservation Center (UAA, ACCC). Alaska Exotic Plants Information Clearinghouse (AKEPIC). Available: http://accs.uaa.alaska.edu/invasive-species/non-native-plant-species-list. [Accessed 18 May 2016]
Lambertini, C., I.A. Mendelssohn, M.H.G Gustafsson, B. Olesen, T. Riis, B.K. Sorrel, and H. Brix. 2012. Tracing the origin of Gulf Coast Phragmites (Poaceae): A long-distance dispersal and hybridization. American Journal of Botany 99(3): 538-551.
Marks, M., B. Lapin, J. Randall. 1994. Phragmites australis (P. communis): Threats, management, and monitoring. Natural Areas Journal 14: 285-294.
Massachusetts Department of Conservation and Recreation (MA DCR). Office of Water Resources: Lakes and Ponds Program. 2002. Available: http://www.mass.gov/eea/docs/dcr/watersupply/lakepond/factsheet/phragmites.pdf. [Accessed 18 May 2016]
Meyerson, L. A., D. V. Viola, and R. N. Brown. 2010. Hybridization of invasive Phragmites australis with a native subspecies in North America. Biological Invasions 12: 103-111.
Meyerson, L.A., C. Lambertini, M.K. McCormick, and D.F. Whigham. 2012. Hybridization of common reed in North America? The answer is blowing in the wind. AoB Plants: pls022.
Michigan Natural Resources Inventory (MNFI). Michigan State University Extension (MSU). 2016. Available: https://mnfi.anr.msu.edu/phragmites/native-or-not.cfm. [Accessed 18 May 2016]
Ministry of Natural Resources (MNR), Ontario. 2010. State of Resources Reporting: Phragmites in Ontario. Available http://www.mnr.gov.on.ca/stdprodconsume/groups/lr/@mnr/@sorr/documents/document/stdprod_086861.pdf. [Accessed 7 September 2011]
Rudrappa, T., Y.S. Choi, D.F. Levia, D.R. Legates, K.H. Lee, and H.P. Bais. 2009. Phragmites australis root secreted phytotoxin undergoes photo-degradation to execute severe phytotoxicity. Plant Signaling & Behavior 4(6): 506-513.
Saltonstall, K. 2002. Cryptic invasion by a non-native genotype of the common reed, Phragmites australis, into North America. PNAS 99 (4): 2445-2449.
Saltonstall, K. 2005. National Park Service (NPS). Plant Conservation Alliances Alien Plant Working Group. Weeds Gone Wild: Alien Plant Invaders of Natural Areas. Available: http://www.nps.gov/plants/alien. [Accessed 18 May 2016]
Saltonstall, K. and D. Hauber. 2007. Notes on Phragmites australis (Poaceae: Arundinoideae) in North America. Journal of Botanical Research Institute of Texas 1:385-388.
Saltonstall, K., H.E. Castillo, and B. Blossey. 2014. Confirmed field hybridization of native and introduced Phragmites australis (Poaceae) in North America. American Journal of Botany 101(1): 211-215.
Silliman B.R., T. Mozder, C. Angelini, J.E. Brunage, P. Esselink, J.P. Bakker, K.B. Gedan. 2014. Livestock as Potential Biological Control Agent for an Invasive Wetland Plant. PeerJ 2:e567.
Swearingen, J. and K. Saltonstall. 2010. Phragmites Field Guide: Distinguishing Native and Exotic Forms of Common Reed (Phragmites australis) in the United States. Plant Conservation Alliance, Weeds Gone Wild. Available http://www.nps.gov/plants/alien/pubs/index.html. [Accessed several times]
Tewksbury, L., R. Casagrande, B. Blossey, P. Hafliger, and M. Schwarzlander. 2002. Potential for Biological Control of Phragmites australis in North America. Biological Control 23:191-212.
University of Michigan-Dearborn. 2016. Native American Ethnobotany Database. Available http://herb.umd.umich.edu/. [Accessed May 31 2016]
United States Department of Agriculture, Natural Resources Conservation Service (USDA, NRCS) The PLANTS Database. National Plant Data Center, Baton Rouge, LA. Available: http://plants.usda.gov/wetinfo.html. [accessed 23 May 2016]
United States Fish and Wildlife Service (USFWS). 2007. Phragmites: Questions and Answers. Available http://www.hpwma.org/user/image/phragmitesfactsheet.pdf. [Accessed 7 September 2011]
Wu, C.A., L.A. Murray, and K. Heffernan. 2015. Evidence for natural hybridization between native and introduced Phragmites australis in Chesapeake Bay watershed. American Journal of Botany. 102(5): 805-812.
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.