Tree 9 - 14 m tall, as wide or wider than tall Leaves: opposite, pinnately compound, 25 - 38 cm long, with five to eleven leaflets. Flowers: either male or female, found on separate plants (dioecious), borne in loosely branched inflorescences (panicles), yellowish green. Fruit: fleshy with a hard stone in the center (drupe), borne in loose clusters, black, 1 cm in diameter, nearly spherical, each stone containing five seeds. Fruit is aromatic when bruised and persists into winter. Bark: grayish brown, becoming furrowed and corky with age. Twigs: orangish yellow to yellowish gray, becoming brown, covered with prominent corky spots (lenticels), strongly scented when scratched. Buds: 3 mm long, elliptic, the scales covered with reddish hairs. Leaf scars: U-shaped, nearly surrounding the buds. Leaflets: shiny dark green, 6.3 - 11.5 cm long, 3 - 6 cm wide, egg-shaped to narrow egg-shaped, non-toothed. Leaves turn yellowish bronze in fall.
Similar species: Phellodendron amurense is rarely seen outside of cultivation, but is easy to distinguish from other species in the Chicago Region. It has corky bark, strongly scented twigs and leaves, and buds almost completely surrounded by the leaf scars. Female trees also have strongly scented, black fleshy fruit containing a five-seeded stone.
Habitat and ecology: Escaped cultivation at the Morton Arboretum. Wild plants were found on the Arboretum grounds and forest preserves nearby.
Occurence in the Chicago region: non-native
Notes: The cork used to stop wine bottles and make bulletin boards is not produced by this species, but rather from Quercus suber, the cork-oak, native to the Mediterranean.
Etymology: Phellodendron comes from the Greek words phellos, meaning cork, and dendron, meaning tree, referring to the corky bark. Amurense means from the region in eastern Asia near the Amur River.