Coefficient of Conservatism:
Coefficient of Wetness:
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.