Phragmites – Oneida County Aquatic Invasive Species Program

Phragmites (Phragmites australis)

Identification: Introduced phragmites forms dense stands including dead stems from previous years. It has hollow woody stems that can grow up to twenty feet tall! The stems are tan and can be ribbed. Leaves are typically 120 – 140 cm long. Each leaf has a blade and a sheath. The sheath wraps tightly around the stem. As seeds mature, the head of the plant starts to look fluffy. Introduced phragmites are blue-green and darker in color than the native phragmites.

Ecology and Natural History: Introduced phragmites is native to Europe. It’s initial introduction was accidental and likely from solid ballast. Later, it was intentionally introduced as a filler plant to stabilize shoreline. It is most likely to be found on disturbed sites. It can grow in damp ground or standing water. It is spread to new locations by seed. A stand can grow larger by rhizomes. One mature plant can produce as many as 2,000 seeds annually! 

Highway 8 West, Rhinelander, WI
Summer 2014
Highway 8 West, Rhinelander, WI
Summer 2015
Do you think you have found non-native phragmites? Contact us for confirmation.