florida Early Detection Network


Common reed


Phragmites australis (Cav.) Trin. ex Steud.


Grass family


Phragmites australis

Size comparison




Close-up of inflorescence

Hairs at Leaf-stem Junction

Inflorescence Variation




Synonyms: Phragmites communis Trin., Phragmites phragmites (L.) Karst.


Botanical Glossary

Phragmites australis is a stout grass that measures 2-4 m (6.5-13 ft.) in height. It is most often seen in large colonies. The stems and leaves are smooth and glabrous. The gray-green leaves are acuminate in shape, 25-50 cm (10-20 in.) long and 2-3 cm (0.75-1 in.) wide. Long white hairs are present at the leaf-sheath junction. The light brown to purple inflorescence is 20-40 cm (7.5-15 in.) long. The spiklets have 3-7 flowers and appear between July and September. The flowers are surrounded by silky white hairs. The first glume is narrowly elliptic and blunt, while the second is linear and nearly twice as long as the first. The lemmas are narrow, 8-12 mm (0.3-0.5 in.) wide. The rachilla hairs are white and as long as the lemmas. However, they are not visible until after the flowers bloom. The seeds are brown, light weight, and about 8 mm (0.3 in.) long. In the fall the plant turns brown, and the inflorescences persist throughout the winter. Page References Crow & Hellquist 261, Gleason & Cronquist 781, Holmgren 732, Magee & Ahles 153. See reference section below for full citations.


Phragmites australis (Cav.) Trin. Ex Steud (Native Phragmites) Recent research has indicated that there are native populations of Phragmites australis in the United States. In 2004 the native populations were described as a subspecies, Phragmites australis subsp. americanus (Article by Saltonstall, Peterson, & Soreng). The native and non-native plants are very difficult to differentiate. invasivespecies.net has a webpage that illustrates the morphological differences between them. It has been shown that most of the New England populations are non-native.


Phragmites australis reproduces by means of wind-dispersed seeds and by long rhizomes.


Phragmites australis is found on every continent in the world except for Antarctica. It is found in every state in the United States except Alaska and Hawaii. It occurs in all of the New England states.


Phragmites australis is native to some parts of the United States, and probably came to New England via natural immigration. It is known to have been in New England for at least 4000 years. Unfortunately, some non-native strains of this plant have also made their way here, and it is suspected that these strains are the ones that have exhibited invasive tendencies.


Coastal Beach or Dune, Coastal Grassland, Edge, Lake or Pond, Open Disturbed Area, River or Stream, Roadside, Salt Marsh, Vacant Lot, Wet Meadow. Phragmites australis can grow in a variety of habitats. It is most often found in wet or marshy areas. This plant grows best in fresh water, but also can be found in brackish, acid or alkaline wetlands. It is also found at the interface between wetlands and uplands.


Though some populations of Phragmites australis may be native to parts of New England, it becomes problematic when it forms huge monocultures that spread for acres, excluding native species. This often happens when it grows in polluted areas that other plants do not tolerate as well. It can form large, thick walls at the interface of upland and wetland habitats. In New England it is clear that this plant has spread beyond its original range, and is now encroaching into wetlands that contain rare native species.


Massachusetts Audubon Society

Plant Conservation Alliance - Fact sheet with management information

The Connecticut Invasive Plant Working Group - Invasive Plant Management Guide


Documentation required: Specific photograph or mounted snippet of the inflorescence. Best time for documentation: Summer


Integrated Taxonomic Information System - Has general taxonomic information about the species.

The PLANTS Database - Distribution information and additional links

Invasiveplants.net - Differences between native and non-native Phragmites

USDA Forest Service Fire Effects Information System - Extensive information including a description and ecology of the species

Ohio Perennial and Biennial Weed Guide - Photographs and description

National Invasive Species Information Center - Links to more information

Virginia Tech Weed Identification Guide - Description and photographs


Britton, N.L. and A. Brown. 1970. An Illustrated Flora of the Northeastern United States vol. 2. Dover Publications Inc., New York.

Crow, G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. Vol 2. University of Wisconsin Press, Madison.

Gleason, H.A. and A.C. Cronquist. 1991. Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden, Bronx, New York.

Graneli, W. 1989. Influence of standing litter on shoot production in reed, Phragmites australis (Cav.) Trin. Ex Steudel. Aquatic Botany 35: 99-109.

Hara, T., J. van der Toorn and J.H. Mook. 1993. Growth dynamics and size structure of shoots of Phragmites australis, a clonal plant. Journal of Ecology 81: 47-60.

Holm, L.G., D.L. Plunckett, J.V. Pancho and J.P. Herberger. 1997. World's worst weeds. University of Hawaii Press, Honolulu.

Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. New York Botanical Garden, Bronx, New York.

Magee, D.W and H.E. Ahles. 1999. Flora of the Northeast. University of Massachusetts Press, Amherst.

Marks, M., B. Lapin, and J. Randall. 1994. Phragmites australis (P. communis): threats, management, and monitoring. Natural Areas Journal 14: 285-294.

Orson, R.A. 1999. A paleoecological assessment of Phragmites australis in New England tidal marshes: changes in plant community structure during the last few millennia. Biological Invasions 1: 149-158.

Ostendorp, W. 1989. "Die-back" of reeds in Europe - a critical review of literature. Aquatic Botany 35: 5-26.

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(4): 2445-2449.

Thompson, D.J. and J.M. Shay, J.M. 1985. The effects of fire on Phragmites australis in the Delta Marsh, Manitoba. Canadian Journal of Botany 63: 1964-1969.

USDA, NRCS. 2001. The PLANTS Database, Version 3.1. (//plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Van der Toorn, J. and J.H. Mook. 1982. The influence of environmental factors and management on stands of Phragmites australis. I. Effects of burning, frost, and insect damage on shoot density and shoot size. Journal of Applied Ecology 19: 477-499.