( lat. Ailanthus )

Kingdom: Plantae
Order: Sapindales
Family: Simaroubaceae
Genus: Ailanthus

Plant Allergy Overview



Pollen Season

Spring Summer





Allergy Information

Ailanthus is a very high pollen producer. This tree has been a moderate source of allergy in the U.S.

Genus Details

The leaves of tree of heaven are 12-24 inches long, broadly lance shaped, and covered with fine hairs when young. The tree can grow to 50 feet tall. Bark is light brown and smooth. Flowers are 1/4 inches long, greenish-yellow in color. The fruit is 1 1/2 inches long, showy, reddish-green in color. Tree of heaven is native to China and has naturalized throughout much of the U.S. It is generally planted in urban areas. This tree is said to be the tree in the classic novel A Tree Grows in Brooklyn, by Betty Smith.

Pollen Description

The tree of heaven has pollen grains that are prolate to subprolate; the amb subtriangular and 3-colporate. The colpi are long and narrow with tapering ends. The sexine is reticulate and the intine is thickened below the apertures.

The grains measure 28-34 x 20-21 micrometers.

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

Species in Plantain Genus

Allergens & Plants Search

Enter a full or partial species name to find more information on one of over 1,200 potentially allergenic plants.
For example, you can find chenopods searching on "cheno"