COMMON NAME
Common reed
FULL SCIENTIFIC NAME
Phragmites australis (Cav.) Trin. ex Steud.
FAMILY NAME COMMON
Grass family
FAMILY SCIENTIFIC NAME
Phragmites australis
IMAGES
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![]() Close-up of inflorescence |
![]() Hairs at Leaf-stem Junction |
![]() Inflorescence Variation |
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![]() Rhizomes |
NOMENCLATURE/SYNONYMS
Synonyms: Phragmites communis Trin.
Phragmites phragmites (L.) Karst.
DESCRIPTION
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.
SIMILAR SPECIES
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.
REPRODUCTIVE/DISPERSAL MECHANISMS
Phragmites australis reproduces by means of wind-dispersed seeds and by long rhizomes.
DISTRIBUTION
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.
HISTORY OF INTRODUCTION IN NEW ENGLAND
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.
HABITATS IN NEW ENGLAND
,Coastal Beach or Dune,Coastal Grassland,Edge,Lake or Pond,Open Disturbed Area,River or Stream,Roadside,Salt Marsh,Vacant Lot,Wet MeadowPhragmites 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.
THREATS
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.
MANAGEMENT LINKS
Plant Conservation Alliance
Fact sheet with management information
The Connecticut Invasive Plant Working Group
Invasive Plant Management Guide
DOCUMENTATION NEEDS
Documentation required: A photograph of the habit, flowers or fruit.
Best time for documentation: Summer, fall.
ADDITIONAL INFORMATION
Adirondack Park Invasive Plant Program
Identification, fact sheet, management and distribution information
Integrated Taxonomic Information System
Taxonomic information
The PLANTS database
General information and map
The Nature Conservancy
Extensive description, images, and control information
Invasiveplants.net
Differences between native and non-native Phragmites australis
USDA Forest Service Fire Effects Information System
Extensive information including a description and ecology of the species
Virginia Native Plant Society
General information including control
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