Cephalanthus occidentalis - Buttonbush
Morphology/Growth Habits: Buttonbush is a deciduous shrub particularly well suited to wet open areas and low-level woodlands. Somewhat rounded habit, although it generally grows in a more open form. Opposite or whorled leaf arrangement and deep green leaf color. Small white, flowers that arrange themselves in spherical clusters, with their exerted styles growing past the petals, making a uniquely vibrant show in the summer. Their globular seedheads typically last through winter until the next bloom!
Height: 6-12 ft
Light: Full Sun-Part Shade
Moisture: Medium-Wet
Bloom color: White
Bloom time: June
Habitat/Best Environments: Common in many wetland habitats such as swamps, streambanks, and riparian zones. As such, it does best in medium-moist soils with partial-full sun. Great option for pollinator gardens, rain gardens, or for erosion control.
Ecological relationships: This shrub has exceptionally high benefits for other species. It is considered a keystone species for wetland ecosystems. The fragrant flowers of this shrub attract many pollinators, including bees, butterflies, and hummingbirds! In our experience at the nursery, leafcutter bees are particularly attracted to this plant, leaving perfectly circular cuts in the leaves when they visit. Seeds are enjoyed by many birds, including waterfowl. Larval host to the hydrangea sphinx, royal walnut moth, and the titan sphinx.
Buttonbush contains glucoside cephalothin, a toxic compound, in all parts of the plant. This can cause vomiting if eaten in large quantities by animals, including humans. This also makes it resistant to rabbits and deer. *Different parts of the plant are used to treat various health issues in Chickasaw, Choctaw, Kiowa, and Muscogee medicine.
*Please soil test and do proper research before growing a plant for human consumption.
Fun facts: Buttonwillow, CA is named after this plant! In the town, there is an old, large buttonbush tree that stands out against the flatlands. This tree was a meeting place for Yokut people. Its first name is ‘Hahlu’, the Yokut word for buttonbush. It was also a landmark on a trans-valley trail, and later used as rodeo grounds by settlers. It is now a California Historical Landmark and still stands to this day!