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Invasive Species Sheet - Common Reed

Invasive Species Identification Sheet

Common Reed (Phragmites australis (Cav.) Trin. ex Steud.)

Alternate Common Names: Phrag; Common Reedgrass; Giant Reed

Some Alternate Latin Names: Phragmites phragmites Karst.; P. maxima (Forssk.) Chiovenda; P. communis Trin.; P. communis Trin. var. berlandieri (Fourn.) Fern.
- very tall grass (6'-15' tall) from perennial rootstock; foliage has bluish-green color
- leaves alternate, stiff; diverging in two rows from hollow, upright culms (stems)
- leaf blades 8"-24" long, flat, up to 1 1/4" wide; edges rough with microscopic teeth
- flowers clustered in a conspicuous plume (8"-16" long) at the ends of the culms above leaves
- flower clusters dark brown with purplish highlights (late July-Oct.) fading to tan
- pale tan, upright dead stems and faded (greyish or pale tan) flower clusters remain in winter

The huge size, bluish-green foliage, thick plume of flowers (often drooping to one side), hollow, dead stalks and plume-like remains of flower clusters that persist even after the following year’s leaf stalks have grown up make it easy to recognize Common Reed throughout the year. Do not confuse with Cattails which have spongy, green basal leaves and persistent dead stems on which the old flower clusters have a matted cotton appearance. At the point where the leaf blade departs from the culm (main stem), there is a horizontal line just below a “microscopic” row of silky hairs, each about 1/32"-1/16" long (use a good hand lens). In addition to this thick row of hairs (the ligule), there may be a few scattered, longer, wavy hair-like growths more readily visible to the naked eye. Common Reed stems remain green one season. Clumps may spread vegetatively 3'-30' per year. The stem beneath the flower clusters has a readily-visible ring of whitish hair. In maturity, long silky hair growing off the stalks within each individual 3-7 flowered spikelet may be seen. Be alert! Long-present, non-invading clumps of Common Reed may be the rarely-seen native race.