Distribution
Argentina (introduced), Australia (introduced), Austria (introduced), Bulgaria (introduced), Canada, China (introduced), Czech Republic (introduced), France (introduced), Germany (introduced), Guatemala, Hungary (introduced), Italy (introduced), Kazakhstan (introduced), Mexico, New Zealand (introduced), Poland (introduced), Russian Federation (introduced), Slovakia (introduced), Spain (introduced), Sweden (introduced), Switzerland (introduced), Turkey (introduced), Ukraine (introduced), United Kingdom of Great Britain and Northern Ireland (introduced), United States of America

Native to: Alabama, Arizona, Guatemala, Illinois, Kentucky, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Missouri, Tennessee, Vermont.
Introduced into: Albania, Algeria, Altay, Argentina Northeast, Austria, Belarus, Belgium, Bolivia, Bulgaria, Buryatiya, Central European Rus, Czechoslovakia, East European Russia, France, Germany, Greece, Hungary, Italy, Kazakhstan, Khabarovsk, Korea, Morocco, New Zealand South, Primorye, Sakhalin, Spain, Sweden, Tadzhikistan, Turkey, Turkey-in-Europe, Turkmenistan, Ukraine, Uzbekistan, Vietnam, West Himalaya, West Siberia, Yukon.

The natural distribution of A. negundo ranges from southern Canada to the mountains of Mexico and as far as Guatemala, is absent from western North America but occurs along the Atlantic coast. The various recognized varieties appear to represent fairly distinct geographic races but these often intergrade (Rosario, 1988). The range of the species has greatly expanded in North America through planting and subsequent natural regeneration and is spreading in the western USA. In Canada, although only native to the southern tip of Ontario, A. negundo is now naturalized in western provinces from Ontario to Nova Scotia (Anon., 1963). The species is widespread in urban areas throughout much of Europe following centuries of horticultural and landscape planting. It is probably more widespread in other temperate regions of the world but is absent from the tropics.

Acer negundo is an often multi-stemmed tree reaching a height of no more than 20 m and a stem diameter of up to 1 m (Rosario, 1988). In more open vegetation the canopy usually exhibits a broad and open crown and may even become shrubby, whereas in the face of competition in a forest stand the trunk tends to be single-stemmed and straighter. Shoots are green and turn violet in the second year. The bark is grey-brown becoming dark grey and is shallowly cracked. Buds are opposite, small, 2-5 mm, two-scaled and silky white. The leaves are 15-35 cm long, pinnate with 3-5 (or 7) leaflets and light green but paler below. The leaflets are lobed and serrated. Leaflet shape is variable, for instance in var. interior the first pair of leaflets is 3-lobed. Male flowers are born in corymbs with pendent stamens whilst female flowers are in small pendent racemes. Both types of flowers are small and pale yellowish-green in colour. There is much variation in the morphology of pistillate flowers with the presence of stamens on a proportion of the flowers (Hall, 1951). The fruit consists of two fused winged samaras to 4 cm long, diverging at an angle of less than 60 degrees. The samaras separate when shed and contain a single wrinkled seed.