Allergy Information

The allergenicity has not been verified in North America, yet may cause pollinosis in late summer. Phragmite communis pollen has been reported to be allergenic in Israel.

Genus Details

Phragmite australis, or common reed, is a tall, perennial reed grass that grows 4-9 feet tall and forms extensive colonies in moist or marshy areas. Common reed grass has lance-shaped leaves up to 20 inches long and 1 inch wide. It produces showy plumed seed heads about 20 inches tall. This grass is native to swamps in North America, Europe and Asia.

Pollen Description

Phragmites pollen grains are similar to other grass grains. They are spheroidal to ovoidal with a thin exine. The grains are 1-porate and the pore is usually circular and surrounded by a thickened ring (annulus) and covered by an operculum.

The pollen grains are approximately 28-30 micrometers in diameter.

Genus Distribution

The shaded areas on the map indicates where the genus has been observed in the United States.

- Native, observed in a county 

- Introduced, observed in a county 

- Rarely observed