A native to China.  A fast growing, usually dense tree with a profusion of tight-knit slender branches.  Light to dark green leaves are alternate, simple, undivided or lobed.  Ovate to broad-ovate, 2" to 7" long and up to 6" wide.  Leaves turn yellow in autumn.  Adaptable to wide range of soil and conditions.  Males are fruitless, but still produce a prodigious amount of pollen in spring.  Surface roots can be a problem, as well as allergies caused by the pollen.