Allergy Information

The grass family in general is considered significant allergenically.

Genus Details

Giant reed is a fast-spreading, stiffly upright tall grass. The leaves are 2 inches long and wide with a spire-like flower plume 2 feet tall. Giant reed is native to South Europe but was brought to the U.S. as an ornamental and has since naturalized. Now it is found along the East Coast and in marshy areas. Giant reed is an abundant pollen producer with July-October the heaviest shedding time.

Pollen Description

The exine is thin and the intine is usually thicker, particularly below the apertures. The surface is granular and the grain has only one circular pore.

Pollen grains of Arundo are spheroidal to ovoidal and 32-45 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