Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Tree-of-heaven, Ailanthus, copal tree
Ailanthus altissima

USDA Symbol:AIAL
ITIS TSN:28827
Presence:Current Invaders
Habitat:Terrestrial
Native Range:China
Toxic Characteristics
Produces an herbicide-like toxin in bark and leaves which prevents the growth of other plant species. Ingestion can cause intestinal distress. May also cause skin irritation.
Geographic Distribution
Naturalized across the United States from Maine to California and south to Texas. Reported in seven Texas counties. Found in the Lower Galveston Bay watershed in Harris county.
Introduction Pathways
This species was brought to the United States in the late 1700s as an ornamental shade tree.
Specific Primary Habitats
Thrives in disturbed soils. It is found in urban areas and along roads and right-of-ways. Inhabits woodland edges and forest openings. Tolerates harsh conditions, varying soil types and light conditions. It cannot tolerate flooding or extreme shade.
Identifying Characteristics
Stems are smooth and light gray to pale brown. Deciduous leaves are 1-4 feet long and alternately compound with up to 25 leaflets. Leaflets have glandular teeth at base. Yellow-green flowers form in the spring on male and female trees.
Reproduction Characteristics
A prolific seed producer within 2-3 years of planting. Winged fruits (samaras) form in dense, hanging clusters in summer-fall. Once dry, seeds are wind or water dispersed in late summer-early spring. Also reproduces vegetatively via root and stump shoots.
Growth Characteristics
Ailanthus is a fast grower. Mature trees can reach heights greater than 80 feet tall and six feet in diameter in approximately ten years.
Ecological, Economic, or Social Impact
Ailanthus can overrun native species and forms dense, monospecific (single species) thickets. Its extensive root system can damage underground pipes and infrastructure.
Control
Foliar, basal bark, cut stump, or hack and squirt herbicide application can be used to control this species. If physically removing a tree, the root system must be removed to avoid regrowth. Fungal pathogens are being studied as control agents as well.

Native Species Alternatives
Below is a list of alternative plants that are native to the area:
  • Wax myrtle (Morella cerifera)
  • Eastern redbud (Cercis canadensis var. canadensis)
  • Mexican plum (Prunus mexicana)
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail.
Ripening samaras (fruit) of the tree-of-heaven. Photo courtesy of Chuck Bargeron, The University of Georgia, www.forestryimages.org; Image Number 1150029.
Ripening samaras (fruit) of the tree-of-heaven. Photo courtesy of Chuck Bargeron, The University of Georgia, www.forestryimages.org; Image Number 1150029.
Large tree-of-heaven. Photo courtesy of Chuck Bargeron, The University of Georgia, www.forestryimages.org; Image Number 1150030.
Large tree-of-heaven. Photo courtesy of Chuck Bargeron, The University of Georgia, www.forestryimages.org; Image Number 1150030.
July foliage of the tree-of-heaven. Photo courtesy of James H. Miller, USDA Forest Service, www.forestryimages.org; Image Number 2307005.
July foliage of the tree-of-heaven. Photo courtesy of James H. Miller, USDA Forest Service, www.forestryimages.org; Image Number 2307005.
Twigs and dried samaras (seeds) of the tree-of-heaven. Photo courtesy of James H. Miller, USDA Forest Service, www.forestryimages.org; Image Number 2307009.
Twigs and dried samaras (seeds) of the tree-of-heaven. Photo courtesy of James H. Miller, USDA Forest Service, www.forestryimages.org; Image Number 2307009.
Flowers of the tree-of-heaven. Photo courtesy of David J. Moorhead, The University of Georgia, www.forestryimages.org; Image Number 1299010.
Flowers of the tree-of-heaven. Photo courtesy of David J. Moorhead, The University of Georgia, www.forestryimages.org; Image Number 1299010.
Close-up of tree-of-heaven leaves with glandular teeth. Photo courtesy of Chris Evans, The University of Georgia, www.forestryimages.org; Image Number 1330079.
Close-up of tree-of-heaven leaves with glandular teeth. Photo courtesy of Chris Evans, The University of Georgia, www.forestryimages.org; Image Number 1330079.
Page Updated/Reviewed: 07/14/2010 8:33 AM
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