American Bladdernut

Staphylea trifolia

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Illustration of American bladdernut leaves, flowers, fruits.
American bladdernut, Staphylea trifoliata
Paul Nelson
Other Common Name
Bladder-Nut
Family

Staphyleaceae (bladdernuts)

Description

American bladdernut is a thicket-forming shrub or small tree, with branches near the top, that produces clusters of bell-shaped white flowers in spring and unusual 3-parted air-filled capsules in late summer that turn papery and persist into winter.

Leaves are opposite, compound, with 3 leaflets, each leaflet 1½–2 inches long, egg-shaped or oval, margins sharply and finely toothed, with a pointed tip. Upper surface bright green, hairy on the veins; lower surface slightly paler, hairy. End leaflet stalk ½–1½ inches long, much longer than the stalks of the side leaflets; side leaflets nearly sessile. Leaflet stalks and petioles hairy. The leaves remain green until late in autumn, eventually turning yellowish green.

Bark is grayish brown, smooth on young shrubs and slightly grooved and flaky on older trunks.

Twigs are flexible, smooth, reddish brown to greenish brown, often striped, curved, ascending.

Flowers April–May, in drooping clusters 2–4 inches long on a short stem arising from upper leaf axils (from twigs of the previous year); flowers small, white, bell-shaped, about ¼ inch long; sepals and petals nearly the same length; petals 5, about ¼ inch long, tips blunt; stamens 5, extending beyond the petals.

Fruits in August, persistent until midwinter, solitary or in clusters of 2–5, strongly inflated, bladderlike, drooping capsules 1¼–2½ inches long, 3-lobed, net-veined, green turning to brown, opening at the tip; seeds 1–4, about ¼ inch long, rounded, somewhat flattened, yellowish to grayish brown, hard, shiny.

Similar species: Another shrub, called hop tree, wafer ash, or stinking ash (Ptelea trifoliata), also has trifoliate leaves, but bladdernut has opposite (not alternate) leaves and a relatively long-stalked central leaflet; the flowers and fruits of the two shrubs are quite different.

Key Identifiers

 

  • Shrub or small tree, usually found in moist soils.
  • Leaves compound with 3 leaflets, the terminal leaflet on a long stalk, the 2 side leaflets nearly sessile.
  • Leaflets oval, pointed-tipped, with teeth.
  • Flowers white, tubular, in drooping clusters.
  • Fruits air-filled, 3-parted capsules that turn brown, dry, and papery, lasting well into winter.
Size

Height: to 25 feet; most typically 10–15 feet.

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Photo of two bladdernut pods held in a hand.
Bladdernut Fruit
When bladdernut fruits form in late summer, they are green, but they later turn brown. They are papery and hang on the tree well into winter.

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Photo of American bladdernut leaves
American Bladdernut Leaves in Fall
American bladdernut has 3-parted compound leaves that arise on opposite sides of the twigs.

American Bladdernut

A cluster of white flowers hang from a leafy stalk.
American bladdernut at Maramec Spring
Habitat and conservation

Occurs, often in thickets, along banks of streams and rivers, bases and sheltered ledges of bluffs, and rich upland forests in ravines, often on north- to east-facing slopes, especially on limestone or dolomite substrates. It is sometimes planted as an ornamental shrub, especially along borders. If you plant it, keep in mind its habit of suckering from the roots, and allow plenty of room.

Distribution in Missouri

Scattered to common statewide.

Status

This is the only member of the bladdernut family native to Missouri. There are only about 10 species in its genus in the whole Northern Hemisphere; globally, the entire bladdernut family includes only 5 genera and some 27 to 50 species. The bladdernut family comprises shrubs and trees whose flowers are 5-parted, with a superior ovary; the fruits are often inflated. A few are garden ornamentals, including the Colchis or Caucasian bladdernut, and the European bladdernut. One of the bladdernut family’s closer relatives is another small family, the Crossosomataceae (crossosomas), which includes the greasebushes and rockflowers of the American Southwest.

Human connections

American bladdernut is a fast-growing, hardy native flowering shrub or small tree that works well in rain gardens, naturalized areas, shade gardens, or woodland areas. It prefers moist soils and part to full shade. It has a tendency to sucker and produces dense colonies in the wild. In spring, the drooping clusters of white, tubular flowers are attractive. The curious, air-filled seed capsules, which mature in late summer and often last into early winter, are a fascinating addition to dried flower arrangements.

Ecosystem connections

Trees and shrubs that thrive and survive in low, moist lowland soils play an important role in stabilizing the land along streams and rivers, preventing erosion, reducing the destructiveness of floods, and creating shady, fertile habitat for many other plants and animals.