Ailanthus altissima (Mill.) Swingle
Coefficient of Conservatism: *
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Ad Tree

Native of China, introduced into North America in 1784 as an ornamental. It is a fast-growing weed tree, sprouting from seeds and suckers, especially in alleys, beside walls and buildings, and in similar narrow places; also in fields, meadows, dumpsites; on shores and river banks; and along railroads. First collected in Michigan in 1892 in St. Clair Co. Doubtless far more widespread than the map indicates, but by-passed by collectors.

This robust smooth-barked tree, with large pinnately compound leaves and large inflorescences of small flowers, is polygamo-dioecious; some trees produce copious elongate samaras with a single central seed. The foliage and especially the staminate flowers are strong-smelling.


Allegan County
Alpena County
Benzie County
Berrien County
Calhoun County
Hillsdale County
Ingham County
Ionia County
Jackson County
Kalamazoo County
Leelanau County
    Including Manitou Islands
Lenawee County
Macomb County
Manistee County
Mason County
Monroe County
Newaygo County
Oakland County
Oceana County
Ottawa County
Shiawassee County
St. Clair County
St. Joseph County
Washtenaw County
Wayne County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 7, 2022.