Tree of Heaven

Ailanthus altissima

Common Name: Tree of Heaven
Scientific Name: Ailanthus altissima
Family: Simaroubaceae
Growth Form: Tree
Native Range: Central China
Invasive Range: The Tree of Heaven has invaded 42 of the 50 United States, including the majority of the East and West coasts.
Introduction: The Tree of Heaven was first brought to the United States by a Philadelphia gardener in 1784.  It was also imported by the many Chinese immigrants who came to California during the gold rush of the 1800s. 
Description: ·Leaves: Compound and toothed, leaflets opposite. Between 13 and 25 leaflets per leaf.  Leaves 30-61 cm (12-24 in.)long. Glands on underside.

·Twigs: Extremely thick, hairy when young.  Pale brown color.

·Bark: Smooth light bark, brown in color. Becomes rough and fissured as tree matures. 

·Flowers: Flowers greenish-yellow in color, 6mm (.25 in.) long.  They occur in clusters at the end of branches.  Male flowers do not smell good.  Flowering occurs in late spring and early summer. 

·Fruit: Fruit appears in early autumn.  Is narrow, flat and winged, with a reddish color.
Threats: The Tree of Heaven grows rapidly and can out-compete native vegetation.  It is able to form an impenetrable thicket and releases toxins that prevent other plants from establishing themselves.  The roots are strong enough to damage sewers, wells, and building foundations.
Fun Facts: The Tree of Heaven grows well in urban environments and has been known to sprout up in the middle of alleys or sidewalks.  This is the tree that was described by Betty Smith in the classic work of fiction, “A Tree Grows in Brooklyn.” 
English ivy on a tree
English ivy taking over a tree
leaf glands