Plant Family: Simaroubaceae
Growth Form: Medium sized to large tree, up to 30 meters tall and 1 meter in diameter.
Leaves: Very large, up to 1 meter long, alternate, once-compound, with 11 – 41 ovate leaflets that have 1 or 2 pairs of rounded teeth at the base; the leaf scars are large and heart-shaped.
Bark: Light gray or brown, smooth to lightly rough.
Flowers: Dioecious, greenish yellow, in terminal clusters, the male flowers have a rank odor, seen in early summer.
Fruits: Large clusters of yellow-green samaras often tinged with red, each holding a single, round seed; they ripen to light brown and may stay on the tree into winter.
Habitat: In its native Asia, Tree-of-Heaven is a generalist, tolerant of a wide range of habitats. It was first planted in European and American cities in the late 18th century, a practice which continued throughout the 19th century, because it is tolerant of drought and pollution, provides shade, and grows where few other trees can survive. It may spread to the wild, however, and is considered by some to be a troublesome weedy tree.
Range: Found throughout most of the U.S. and eastern Canada, primarily in urban and suburban areas.
Similar Species: The leaves could possibly be confused with Black Walnut or Butternut, but those trees have lightly toothed leaflets that lack the larger basal pair(s) of teeth.
Comments: The common name refers to the extremely fast growth rate of young trees, as much as 2 to 3 meters in a growing season! And, of course, Tree-of-Heaven is the central metaphor of the popular American novel, A Tree Grows in Brooklyn.
