Allergy Information

Acacia plants have been reported to cause pollinosis, even though they produce sparce pollen and are insect-pollinated. In Israel, Acacia pollen is considered strongly allergenic. In the U.S., they have less notoriety.

Genus Details

The acacia genus contains primarily tropical and subtropical trees and shrubs, native primarily to Australia and Africa. Species native to North America grow in the hot, arid SW region of the U.S. Leaves are bipinnately compound with small compact, light yellow flowers and numerous prominent stamens (male pollen-bearing structure), 10 or more. Since acacias are in the legume or pea family, the fruits are dry pods. The short-lived trees grow rapidly up to 50 feet in height. Powdered acacia gum or gum arabic is used to thicken foods and pharmaceuticals. Inhalation of the powder can cause allergic symptoms.

Pollen Description

Most species of Acacia have 16 cells in the polyad but a few species have 48 (A. farinosiana and A.carenia). The intine of the grains is thin.

Pollen grains of Acacia form polyads and reach 38-52 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