Distribution: Occurring chiefly east of the Cascades crest in Washington, British Columbia to California, east across most of North America to the Atlantic Coast.

Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.

Flowers: May-July

Origin: Introduced from China

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Beetles

Large, fast-growing, smooth-barked, sub-dioecious trees.

Leaves very large, alternate, pinnate, deciduous, glabrous or puberulent; leaflets 10-25, the terminal one often absent, lance-ovate, 4-15 cm. long, with 1-3 coarse, rounded teeth on each side near the base, each tooth bearing a gland on the lower side.

Inflorescence a large, open panicle; flowers small, greenish, 6-8 mm. broad, ill-scented; sepals 5, persistent; petals 5, deciduous; stamens 10 on the perfect and staminate flowers.

Samaras 2.5-5 cm. long, spirally twisted.