Bladdernut is a large shrub or small tree that is fairly common in rich bottomland forests, especially along streams. The three-parted, opposite, toothed leaves are distinctive. Hoptree (Ptelea trifoliata) also has trifoliate leaves, but the leaves are alternate and it's a rare shrub of drier areas. Boxelder (Acer negundo) is much larger and has more coarsely toothed leaves.

Durham Co., NC 6/21/2009.

Orange Co., NC 6/3/2012.

Leaves are paler beneath and slightly hairy.

Durham Co., NC 6/21/2009.

Bladdernut is one of the earlier trees to break bud, a little later than Painted Buckeye, but earlier than the overstory trees. These flower buds are just about to open.

Eno River, Durham Co., NC 4/5/2014.

Pendant bell-shaped flowers appear in late March to mid-April, here with old dry seed pods from the previous year.

Durham Co., NC 3/25/2012.

Durham Co., NC 3/25/2012.

Durham Co., NC 3/25/2012.

Eno River, Durham Co., NC 4/11/09.

Eno River, Durham Co., NC 4/11/09.

Eno River, Durham Co., NC 4/11/09.

Chapel Hill, NC 4/14/02.

Chapel Hill, NC 4/14/02.

The flowers are followed by bladder-like, air-filled seed pods, which ripen in the fall.

Caswell Co., NC 5/21/10.

Orange Co., NC 6/3/2012.

Orange Co., NC 6/3/2012.

Durham Co., NC 6/21/2009.

Durham Co., NC 6/21/2009.

Chatham Co., NC 6/18/05.

The bark is tight or slightly ridged, with whitish striations.

Orange Co., NC 6/3/2012.

Bladdernut usually grows on river and stream banks.

Eno River, Durham Co., NC 4/11/09.