Allergy Information

Although the grass family in general is considered significant allergenically, this genus is not typically considered to be problematic.

Genus Details

Rice grass is native to the U.S. and found extensively throughout the western states. It's a hardy grass that grows well in cool temperatures. This grass reaches 4 to 24" in height. Rice grass has extensive roots and is extremely drought tolerant. It grows best in dry, sandy soil and is tolerant of both acidic and basic soil types. The seeds shed from this grass resemble rice grains.

Asthma Description

Grains are spheroidal to ovoidal, sometimes elliptical. The exine is thin and the surface is granular to finely reticuloid. Poaceae apertures are 1-porate, with the pores usually circular to ovoidal.

Grains are 22-122 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