Some 6-11 species of deciduous shrubs (spirea-like), tall, exfoliating bark. Leaves alternate, simple, usually 3-lobed, conspicuous stipules soon abscising. Flowers in terminal clusters (corymbs), white, calyx 5-lobed, 5 petals, numerous stamens, 1-5 carpels, usually 5. Fruit is a small follicle which bursts open at both seams. Nearly all species are native to North America, one (P. amurensis) is found in Manchuria and Korea.
Physocarpus: from the Greek physa, bladder, and karpon, a fruit, a reference to the small, bladder-like fruit.