Common Reed

Phragmites australis australis

common_reed_colony.jpg

Photo of common reed plants in large colony
Bernd Blossey, Cornell University, Bugwood.org
Edible
Invasive
Family

Poaceae (grasses)

Description

A grass with very tall, hollow stems. Long, flat leaves spread out widely from the stem, growing 4 to 20 inches long and 1 to 1½ inches wide, with rough edges and a fine tip. The leaf collar, or ligule, a small outgrowth where the stem and leaf join, is a ring with dense, stiff hairs. Tawny, purplish flowers have long, silky hairs and occur in a large, plumelike panicle 6 to 20 inches long. Blooms in midsummer; seed set by late September.

Size

Height: to 15 feet.

common_reed_flowers.jpg

Photo of common reed showing purplish flowers
Common Reed (Flowers)

common_reed_fall.jpg

Photo of common reed, late-season mature plants
Common Reed (Mature Seedheads)

common_reed_leaf_base.jpg

Photo of common reed, closeup of leaf collar
Common Reed (Leaf Collar)
Habitat and conservation

Common reed occurs in disturbed or pristine wetlands, including shores of ponds and lakes, marshes, springs, riverbanks, roadsides, and ditches. It grows best in areas with slow or stagnant water and is able to tolerate frequent, prolonged flooding, seasonal drying, and moderate salinities. It prefers full sun and it is generally shade intolerant.

image of Common Reed distribution map
Distribution in Missouri

Currently established in 26 Missouri counties.

Status

Invasive. Occurs throughout Europe, Asia, Africa, and Australia. It was most likely introduced to North America by accident in ballast material during the 1800s.

Life cycle

Common reed usually spreads vegetatively by aboveground stolons (lateral shoots that root to form new plants) and belowground rhizomes. Dense clusters can form with 8-20 stems per square foot. Stolon growth and seed germination occur in exposed moist soils during times of low water. New populations can be established from small rhizome fragments or by seeds, which can be dispersed by wind or water.

Human connections

Worldwide this reed has been used for roof thatching, basketry, and more. Unfortunately, the invasive subspecies of common reed (P. australis australis) is currently being promoted and used for constructed wetlands as a treatment for municipal sewage in at least four Missouri municipalities.

Ecosystem connections

Its vigorous rhizomatous growth often results in dense, impenetrable stands, altering diversity in natural wetlands. The thick litter and dense vegetative growth prevents native plant species from growing and can alter an area's hydrology. Wetland wildlife habitat is substantially degraded.