Ailanthus altissima (P. Mill.) Swingle




All photographs are copyrighted and are the property of E. Brunner.

Family:  Simaroubaceae

Native or Introduced to Illinois: introduced 

Natural Habit in Illinois:  Species is distributed in disturbed woods, waste ground, dumps, alleys.

Leaf:  Alternate, pinnately compound with 1 to 3 foot leaves, feather-like, with 11 to 41 leaflets. Leaflets are 2 to 6 inches long, pointed at the tip with large, glandular teeth near the base.

Flower:  Flowers open in mid-April to July. Staminate flowers have a disagreeable odor. Petals are yellow-green.

Fruit:  An oblong, twisted samara, 1 to 1 1/2 inches long with the seed in the center. Ripens September to October and dispersed over the winter.

Twig:   Coarse, yellow to red-brown, with fine velvety hairs when young. Easily broken with reddish-brown pith. Buds are relatively small and half-spherical sitting above large, heart-shaped leaf scars. Terminal bud is absent.

Bark:  Thin, light brown to gray, becoming somewhat rough. Often resembles the skin of a cantaloupe.

Size/Form/Shape:  A short to medium-sized tree with heavy branches. Lower branches on larger trees tend to droop. Often grows in clumps.

County Distribution Map for Illinois:  


Sources for the Sullivan Middle School Tree Identification Guide were obtained though the use of the following sites: