Plant

Common Reed Grass

Common reed grass (Phragmites australis ssp. australis) is an invasive perennial grass that is native to Eurasia. It is not known for certain how it was moved to North America, but it likely arrived on the Atlantic coast accidentally via ballast materials in the late 1700s - early 1800s. (Swearingen, J. and K. Saltonstall. 2010)

Since establishing in North America, Phragmites australis ssp. australis has spread throughout continental U.S. and to most provinces in Canada. It prefers to grow in standing water but will tolerate growing in dryer areas. It can easily be confused with a closely related native subspecies, Phragmites australis ssp. americanus.

Identification

Here are some key features that may help positively identify Common Reed Grass and distinguish it from its native relative:

Phragmites australis ssp. australis (Invasive):
  • Grows in dense stands and crowds out other species
  • Grows to be ~5 m tall, a much more robust plant than the native Phragmites
  • Lower stems are tan or beige-coloured
  • Leaves are arranged alternately and are a blue-green colour
  • The panicle inflorescence (seed head) is larger and more full than the native subspecies'
  • Begins growing earlier in the spring and grows later into the fall than the native subspecies
  Phragmites australis ssp. americanus (Native):
  • Grows in a more scattered manner, mixed in with other native wetland species
  • Typically reaches 2 m in height
  • Lower stems are red
  • Leaves are yellowish-green, smaller than invasive Phragmites', and distributed predominantly on the same side of the stem
  • The panicle inflorescence (seed head) is smaller and more sparse
 
Image gallery
Stand of Phragmites australis ssp. australis. Photo by James H. Miller, USDA Forest Service, Bugwood.org
Stand of Phragmites australis ssp. australis. Photo by James H. Miller, USDA Forest Service, Bugwood.org
Invasive Phragmites australis ssp. australis along a US road. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Invasive Phragmites australis ssp. australis along a US road. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Phragmites australis ssp. australis panicle. Photo by Caleb Slemmons, National Ecological Observatory Network, Bugwood.org
Phragmites australis ssp. australis panicle. Photo by Caleb Slemmons, National Ecological Observatory Network, Bugwood.org
Leaf sheaths of Phragmites australis ssp. australis cling tightly around the stem. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Leaf sheaths of Phragmites australis ssp. australis cling tightly around the stem. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Native Phragmites australis ssp. americanus in foreground. Photo by Rosemary Curley, PEIISC.
Native Phragmites australis ssp. americanus in foreground. Photo by Rosemary Curley, PEIISC.
Red lower stems of the native Phragmites australis ssp. americanus. Photo by Rosemary Curley, PEIISC.
Red lower stems of the native Phragmites australis ssp. americanus. Photo by Rosemary Curley, PEIISC.

Map

See where Common Reed Grass has been reported on Prince Edward Island

Map »