Buttonbush (Cephalanthus occidentalis) at Rick Gonzales, Sr., Park. Photo by queerbychoice. Photo by queerbychoice.Buttonbush (Cephalanthus occidentalis) is a shrub in the madder family (Rubiaceae). The madder family also contains Cleavers.
Buttonbush is also called Button-willow because it grows in similar conditions to willow trees. However, it is not closely related to willows.
Buttonbush is a deciduous shrub that is native to wetlands areas in all of Woodland and most of Yolo County, particularly in the Sacramento Valley portion of the county. It grows only in wet areas and needs about as much moisture as a regularly watered lawn. It prefers full sun and can tolerate zero-drainage situations.
Buttonbush usually grows 3 to 8 feet tall by 3 to 6 feet wide, but with enough access to water, it can occasionally reach 20 feet tall and 15 feet wide. In early spring, its new leaves emerge in shades of brilliant orange. The leaves turn green as they mature. In summer and fall, the shrub is covered in spherical, cream-colored flower clusters that are each about one inch wide.
The Arboretum Nursery at UC Davis sometimes sells a patented cultivar called Cephalanthus occidentalis 'SMCOSS' PP26543 Sugar Shack®. This is a dwarf variety that stays 3 to 4 feet tall and equally wide. This variety produces red fruit rather than the usual green fruit.
Buttonbush has "perfect" flowers (containing both male and female parts in a single flower). It is ranked 5 out of 10 on the Ogren Plant Allergy Scale, indicating a mild to moderate tendency to cause hay fever.
Buttonbush (Cephalanthus occidentalis) blooms at Rick Gonzales, Sr., Park, September 2023. This picture shows small green fruits, a browned, spent flowerhead, and an out-of-focus white flowerhead at peak bloom. Photo by queerbychoice.
Buttonbush (Cephalanthus occidentalis) new foliage matures from red to green over the course of the month of April. Photo by queerbychoice.
Buttonbush (Cephalanthus occidentalis) new foliage emerges flame-colored in April. Photo by queerbychoice.
