Buttonbush

Cephalanthus occidentalis
Family: Rubiaceae

Natural History
Opposite leaves and spherical flower clusters of buttonbush
Photo credit: Larry Korhnak, University of Florida

Buttonbush is abundant in low lands, sometimes becoming large thickets. It can be a bothersome plant for landowners near or in wetlands. It has a wide range, extending from southeastern Canada and Minnesota through the eastern U.S. to Texas and Cuba, Several varieties also occur in the Southwest and Mexico. This wide range reflects the capacity of buttonbush to tolerate a variety of environmental conditions.

It is not commercially valuable, but buttonbush does make a nice ornamental because of its attractive flowers.

On low-lying pasturelands, buttonbush can be harmful because its foliage is poisonous to cattle. Many birds and other wildlife use the dense thickets of buttonbush for cover and nesting. Ducks and songbirds enjoy the nutlets of the round clusters of maroon-colored fruit.

Buttonbush is easily recognized by its simple leaves, opposite leaf arrangement, and spherical flower heads occurring in clusters of two or more. The many tiny flowers bloom throughout the summer.


 

Identifying Characteristics

Habitat: Buttonbush grows in wetlands around the borders of swamps, ponds, and rivers.
Size/Form: Buttonbush can be thickets of shrubs or small trees that reaches heights 25' to 35' tall.
Bark: The gray-brown bark is smooth.
Leaves: The leaves are simple, oppositely arranged, and deciduous. The leaves are 4" to 7" long and 2" to 3 ½" wide. They are elliptically shaped, papery thin, slightly hairy underneath, and have smooth margins. The leaf base is rounded or wedged and the leaf tip is short- to long- tapering.
Flowers: The fragrant white flowers are borne in ball-shaped clusters, 1" to 1½" in diameter.
Fruit: The fruit are tiny dark red-brown achenes in spherical clusters that measure ¾" in diameter.

 

Images

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