Buttonbush

Scientific Name: Cephalanthus occidentalis. The Greek words kephale (head) and anthos (flower) combine to become the genus Cephalanthus. The species name, occidentalis, is a Latin word meaning “from the west.”¹

Common Name: Buttonbush. What do you see when you look at the seedheads? They remind some folks of buttons, hence the common name buttonbush! Other similar names include button ball and button willow. They’re also known as honey-bells or honeyball because the flowers are a great source of nectar for honeybees!^5,13

Family: Rubiaceae (Madder Family). A family of roughly 13,000 species across over 600 genera. Plants in this family are found across the globe, but are more often found in tropical and subtropical regions. Do you enjoy coffee? You will be interested to know that almost all coffee beans come from two species of coffee plants, Coffea arabica and Coffea canephora, which are in the Rubiaceae family!^3,4

Plants in the Rubiaceae family are trees, shrubs, or herbs with unlobed, untoothed leaves that are arranged opposite each other or in whorls. The type of leaf on a given species varies widely depending on its habitat, and is often needlelike in the desert, deciduous in temperate areas, and evergreen in tropical areas. Flowers often have 4–5 petals, and flowers may grow in a cluster or singly. Fruits may be berries, drupes (with a pit like a plum), or nutlets.³⁴

Average Height: 6-12 feet, but may reach 20 feet

Description: Cephalanthus occidentalis is a many-branched deciduous shrub. The swollen bases of the individual stems help stabilize the plant. Young branches are green or red and have raised lenticels. The elliptical leaves measure up to 6” long and 3” wide, and are either in pairs or whorls. The untoothed, bright green leaves are glossy above. Flowers are borne on branching flower stalks with 1–3 ball-like flowerheads. The flowerheads are made up of tightly packed tubular white flowers (each roughly ⅓” long) and are about 1 ½” across. Long styles extend well past the flower tubes and make the flower head look like a pincushion. The spherical seed heads are made up of individual nutlets—small dry fruits each with two seeds. These seed heads turn from red to brown as they mature.^1,2,4,5,7

Bloom time: Jun – Jul

Notes: The ball-like flower heads and fruit, combined with the opposite (or whorled) leaves, make this wetland shrub very distinctive.^4,5

Range: This plant is frequent or locally common throughout Virginia, though missing from some counties to the south and west. Buttonbush occurs in the eastern, central, and southern parts of the US and Canada, from Nova Scotia and Maine west to Minnesota, south to Texas (including Nebraska, Kansas, and Oklahoma), and east to Florida. It can also be found in New Mexico, Arizona, and California.^8,9,10

Geology/Soil: Prefers moist to wet rich soils, and can tolerate heat, soil compaction, flooding, and up to several feet of standing water, but does not do well in dry soils.^1,6

Habitat: Grows in a variety of wetland habitats which are seasonally or semi-permanently flooded including floodplain pools, swamps, bogs, marshes, edges of lakes and streams, as well as ditches and other disturbed wetlands.^5,6,8

Flora associations: Found with other species that prefer moist to wet soils. This may include woody species such as red maple (Acer rubrum), pin oak (Quercus palustris), green ash (Fraxinus pennsylvanica), grapes (Vitis spp.), poison ivy (Toxicodendron radicans), and herbaceous plants such as broad-leaved arrowhead (Sagittaria latifolia), white turtlehead (Chelone glabra), woolgrass (Scirpus cyperinus), arrow-leaf tearthumb (Persicaria sagittata), and sedges (Carex spp.).

Fauna associations: Many butterflies, bees (including bumblebees, green metallic bees, and leaf-cutting bees), wasps, and flies are attracted by the nectar and pollen of the flowers. Even ruby-throated hummingbirds (Archilochus colubris) may pay a visit to drink the nectar!^2,13

Cephalanthus occidentalis is a host plant for many species of moths, including the titan sphinx (Aellopos titan), the hydrangea sphinx (Darapsa versicolor), two Momphid moths (Mompha cephalonthiella and M. solomoni), and the gold-lined melanoma moth (Melanomma auricinctaria). Look at the common and scientific names of these insects: the buttonbush leaf beetle (Calligrapha cephalanthi), the buttonbush gall midge (Rabdophaga cephalanthi), the buttonbush aphid (Aphis cephalanthi), and the buttonbush mite (Aceria cephalanthi). They all depend closely on buttonbush!^2,12,13

The seeds of buttonbush are eaten by birds, including waterfowl. Wood ducks, common grackles, and king rails have been documented using buttonbush for nesting sites. The wood of buttonbush is used by beavers for food and as a construction material.^2,5,13

Human associations: Today, buttonbush is planted as an ornamental and to help prevent erosion. Cephalathin, a poison found in buttonbush (Cephalanthus occidentalis), may cause vomiting, convulsions, and paralysis. Over time, Indigenous people have found a variety of medicinal uses for Cephalanthus occidentalis. The Choctaw use decoctions of the bark to treat dysentery and sore eyes, while the bark is used for fever and toothache. Other uses include treating headaches, nausea, diarrhea, and stomach aches.^5,11

We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!

1 “Cephalanthus Occidentalis – Plant Finder.” Www.missouribotanicalgarden.org, www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=g830. Accessed 13 Jan. 2025.

2 “Buttonbush (Cephalanthus Occidentalis).” Www.illinoiswildflowers.info, www.illinoiswildflowers.info/trees/plants/buttonbush.htm. Accessed 13 Jan. 2025.

3 “Rubiaceae | Description, Characteristics, Species, & Facts.” Encyclopedia Britannica, www.britannica.com/plant/Rubiaceae. Accessed 13 Jan. 2025.

4 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, pp. 900-912.

5 Wennerberg, Sarah, and Mark Skinner. “Plant Guide COMMON BUTTONBUSH”. United States Department of Agriculture Natural Resources Conservation Service. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_ceoc2.pdf. Accessed 13 Jan. 2025.

6 “Cephalanthus Occidentalis (Buttonbush) | North Carolina Extension Gardener Plant Toolbox.” Plants.ces.ncsu.edu, plants.ces.ncsu.edu/plants/cephalanthus-occidentalis/. Accessed 13 Jan. 2025.

7 “Virginia Tech Dendrology Fact Sheet.” Vt.edu, 2021, dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=179. Accessed 13 Jan. 2025.

8 “Digital Atlas of the Virginia Flora | Cephalanthus Occidentalis L.” Vaplantatlas.org, 2025, www.vaplantatlas.org/index.php?do=plant&plant=2610&search=Search. Accessed 13 Jan. 2025.

9 “NatureServe Explorer 2.0.” Natureserve.org, 2024, explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.140322/Cephalanthus_occidentalis. Accessed 13 Jan. 2025.

10 “2014 BONAP Maps by States.” Bonap.net, 2025, bonap.net/FieldMaps/Home/SingleMap?taxonId=21992&mapType=County. Accessed 13 Jan. 2025.

11 “BRIT – Native American Ethnobotany Database.” Brit.org, 2025, naeb.brit.org/uses/search/?string=cephalanthus+occidentalis. Accessed 13 Jan. 2025.

12 “Search: Cephalanthus occidentalis.” Bugguide.net, 2024, bugguide.net/index.php?q=search&keys=cephalanthus+occidentalis. Accessed 13 Jan. 2025.

13 Wheeler, Justin. “Planting for Pollinators: Button Bush.” Xerces Society, 26 Oct. 2017, xerces.org/blog/planting-for-pollinators-button-bush. Accessed 13 Jan. 2025.

Definitions:

Lenticel: A lens-shaped area on the surface of a stem or root that is slightly raised.

Nutlet: A small nut.

Style: The part of a flower which connects the stigma (part that receives pollen) to the ovary.

Whorl: A ring-like arrangement of similar parts issuing from a common point.