Allergy Information

The mountain cedar (Juniperus asheii) species has been found to have significant allergenic properties. Research has named this to be of similar allergenicity to ragweed, one of the most allergenic pollen types.

Genus Details

Juniperus is a family of about 70 species of evergreen trees and shrubs, many of which are called " cedars". Other common names include mountain cedar, cedar juniper, and juniper redberry. Juniperus is widely distributed throughout North America, although certain species are more allergenic than others. Juniperus asheii is a species found in the southern states, with the largest population found on the Edwards Plateau in Texas. Because there are many types of juniper found in this area and the pollen grains are so similar, it is often hard for an individual to determine which species are allergenic to them. When weather conditions are supportive, pollen can travel many miles.

Asthma Description

Grains are usually spheroidal with a thin exine.The grains are 1-aperturate with a faint circular pore. The pollen grains are uniform within the family and different genera are difficult to distinguish.

Grains are 25-36 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