Last Updated: Spring 2012
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Phragmites communis Trin.
Phragmites phragmites (L.) Karst.
Home Range/U.S. Introduction:
Three separate lineages of Phragmites occur in the United States: one native that is endemic and widespread, one from Europe that is invasive, and a third with an unknown native range which occurs across southern U. S from California to Florida and is known as the “Gulf Coast type”. The invasive Phragmites was probably introduced in the late 1700s or early 1800s in ballast water. The three lineages are now separated into Phragmites australis (Cav.) Trin. Ex Steud. (invasive); Phragmites australis ssp. americanus Saltonstall, Peterson and Soreng (native); Phragmites australis ssp. berlandieri Saltonstall and Hauber (Gulf Coast type).
U.S. Range Map:
USDA, NRCS. 2012. The PLANTS Database (http://plants.usda.gov, 18 June 2012). National Plant Data Team, Greensboro, NC 27401-4901 USA.
General characteristics: Common reed is a tall, coarse perennial with stout rhizomes to 2 cm across, deep seated in the substrate. The stems are stout up to 4 m tall, 5-15 mm thick, terete, smooth. The sheaths are open not keeled. The leaves are flat, stiff, 1-6 cm broad and to 6 dm long, serrate, tapering to long-attenuate tips. The ligule is a ring of dense short stiff hairs. The inflorescence is a plumelike panicle, tawny to purplish or silvery, 15-50 cm long, 2 dm broad, with many branches. The internodes between the flowers (i.e. the rachilla) have long silky hairs.
The most reliant method for separating the native Phragmites (haplotypes A, H, S, Z, AA, AB, AC) from the invasive European introduction (haplotype M) or the “Gulf Coast type” (haplotype I) is through DNA analysis. However, some morphological characters can be useful in the field to separate native Phragmites from the invasive species. The Gulf Coast haplotype and the invasive haplotype are very similar morphologically and DNA analysis must be used to separate them. The following table lists some of the characters that might be useful for separating native and invasive Phragmites in the field.
Plants grow in marshes, shores, often in tidal waters, along streams, lakes and estuaries. The invasive Phragmites is more likely to be found in disturbed sites such as roadsides, construction areas, agricultural fields, or along developed shorelines. Colonies of the introduced species tend to be denser than those of the native subspecies. Plants can form extensive colonies from rhizomes. Spread is by wind or waterborne seeds or vegetatively through rhizomes or rhizome fragments.
The invasive subspecies can be dominant over large areas, excluding other vegetation thus decreasing biodiversity. It also alters wetland hydrology, increases fire potential, and reduces and degrades wildlife habitat for wading birds and waterfowl.
Batterson, T. R. and D. W. Hall. 1984. Common reed - Phragmites australis (Cav.) Trin. ex Steudel. Aquatics 6(2): 16-17, 20.Gould, F. W. 1968. Grass Systematics. McGraw-Hill, Inc., New York.
Marks, M, B. Lapin, and J. Randall. 1994. Phragmites australis (P. communis): Threats, management, and monitoring. Natural Areas Journal 14(4): 285-294.
Saltonstall, K. 2002. Cryptic invasion by a non-native genotype of Phragmites australis into North America. Proceedings of the National Academy of Sciences, USA 99: 2445-2449.
Saltonstall, K. 2003. A rapid method for identifying the origin of North American Phragmites populations using RFLP analysis. Wetlands 23: 1043-1047.
Saltonstall, K., and D. Hauber. 2007. Notes on Phragmites australis (Poaceae: Arundinoideae) in North America. J. Bot. Res. Instl Texas 1: 385-388.
Saltonstall, K., P. M. Peterson, and R. Soreng. 2004. Recognition of Pragmites australis subsp. Americanus (Poaceae: Arundinoideae) in North America.
Swearingen, J. and K. Saltonstall. 2010. Phragmites Field Guide: Distinguishing native and exotic form on common reed (Phragmites australis) in the United States. Plant Conservation Alliance, Weeds Gone Wild. http://www.nps.gov/plants/alien/pubs/index.htm
Tarver, D. P., J. A. Rogers, M. J. Mahler, and R. L. Lazor. 1986. Aquatic and Wetland Plants of Florida. Third Edition. Florida Department of Natural Resources, Tallahassee, Florida.