Overview
Native to northeastern and central China. Typically lives to 50 years old, though some specimens can live over 100 years. The tree was brought to the US in 1784 as an ornamental and has been found in nearly all continental states. Plant releases allelopathic chemicals, which suppress the growth of other plant species. If a tree is cut down, it aggressively resprouts from the roots making control difficult.

Appearance

Ailanthus altissima is a rapidly growing, typically small deciduous tree up to 80 ft. (24.4 m) in height and 6 ft. (1.8 m) in diameter. It has large, heart-shaped leaf scars on the twigs. Bark is smooth with lenticels and light grey, developing fissures as it grows older. Leaves and other plant parts smell like rancid peanut butter.

Foliage

Foliage is one of the best identifying characteristics for this species. The leaves are pinnately compound and 1-4 ft. (0.3-1.2 m) long with 10-41 leaflets. Ailanthus altissima resembles native sumac and hickory species, but it is easily distinguished by the glandular, notched base on each leaflet. 

Flowers

Species is dioecious (separate male and female plants) and flowering occurs in early summer when large clusters of small yellow flowers on 20 inch long stems develop above the foliage.

Fruit

Fruit produced on female plants are tan to reddish, single winged with one seed in the middle and can be wind or water-dispersed. Fruit can remain on the tree through the winter. A single tree can produce 325,000 seeds per year.

Ecological Threat

Ailanthus altissima forms dense, clonal thickets which displace native species and can rapidly invade fields, meadows, and harvested forests. This invasive tree species is extremely tolerant of poor soil conditions and can even grow in cement cracks. Ailanthus altissima is not shade tolerant, but easily invades disturbed forests or forest edges causing habitat damage. Introduced as an ornamental, it was widely planted in cities because of its ability to grow in poor conditions. Management and control efforts for this species continue across the United States at great economic cost.

Citation
Winston, R.L., C.B. Randall, B. Blossey, P.W. Tipping, E.C. Lake, and J. Hough-Goldstein. 2017. Field Guide for the Biological Control of Weeds in Eastern North America. USDA Forest Service, Forest Health Technology Enterprise Team, Morgantown, West Virginia. FHTET-2016-04. Retrieved from http://bugwoodcloud.org/resource/pdf/FHTET-2016-04_Biocontrol_Field_Guide.pdf
 

Resources

• A Field Guide for the Identification of Invasive Plants in Southern Forests - USDA Forest Service
• Southeast Exotic Pest Plant Council Invasive Plant Manual - SE-EPPC
• Element Stewardship Abstract - The Nature Conservancy
• Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
• Weed of the Week - USDA Forest Service
• Weed Field Guide - USDA Forest Service
• Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service

Selected Images

Maps

Invasive Listing Sources

• Alabama Invasive Plant Council
• Arizona Noxious Weeds
• California Invasive Plant Council
• City of Ann Arbor Michigan Parks and Recreation
• Colorado Noxious Weeds
• Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, 1994.
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Delaware Invasive Species Council
• Delaware Invasive Species Council Invasive Species List
• Georgia Exotic Pest Plant Council - Category 1
• Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
• Indiana Invasive Species Council - Invasive Plant List
• Indiana Terrestrial Plant Rule
• Invasive Plant Species of West Virginia
• Invasive Species of Concern in Georgia
• Iowa Forest Invasive Plants
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Kentucky Exotic Pest Plant Council - Severe Threat
• Maine Invasive Plants
• Maryland Cooperative Extension Service.  2003. Invasive Plant Control in Maryland. Home and Garden Information Center, Home and Garden Mimeo HG88. 4 pp.
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• Maryland Invasive Species Council - Invasive Species of Concern in Maryland
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• Minnesota Noxious Weeds
• Missouri SRISP Species List
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Native Plant Society of Oregon, 2008
• New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture,  Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
• New Hampshire Prohibited Invasive Species
• New Jersey Invasive Species Management Act
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• New Mexico Noxious Weeds
• Non-Native Invasive Plants of Arlington County, Virginia
• Non-Native Invasive Plants of the City of Alexandria, Virginia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Ohio Invasive Species Council
• Ontario’s Invading Species Awareness Program Tracked Species List
• Oregon Noxious Weeds
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Pennsylvania Noxious Weeds
• Plant Invaders of Mid-Atlantic Natural Areas
• Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
• Rhode Island Natural History Survey
• South Carolina Invasive Pest Council
• Tennessee Exotic Pest Plant Council
• Vermont Noxious Weeds
• Virginia Invasive Plant Species List
• Virginia Invasive Species Management Plan 2012
• Virginia Noxious Weeds
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Department of Agriculture Regulations Governing the Distribution of Plant Materials
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• West Virginia Noxious Weeds
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References