Cephalanthus occidentalis, commonly known as Common Buttonbush, is a deciduous shrub or small tree native to wetlands, including swamps, marshes, and along streams and lakes in the Eastern USA, parts of California’s Central Valley, and Mexico. It typically grows 1–3 m (3.3–9.8 ft) tall and wide, with leaves arranged oppositely or in whorls of three. The distinctive flowers are tiny, tubular, and creamy white, clustered into dense, spherical heads 2–3.5 cm (0.79–1.38 in) in diameter, blooming from June to September. The fruit is a cluster of nutlets that provide food for waterfowl. Buttonbush is valued for its unique flower form, attractiveness to pollinators, and its adaptability to wet conditions.

Buttonbush thrives in full sun to part shade and prefers wet, poorly drained soils, making it ideal for rain gardens and naturalized wetland plantings. It is also used in butterfly gardens due to its appeal to various butterfly species. While it is tolerant of occasional flooding and standing water, it is less suitable for dry sites. Gardeners should be aware that Buttonbush can spread aggressively in optimal conditions, potentially becoming weedy. It is resistant to most pests and diseases but can suffer from leaf spot and rust.CC BY-SA 4.0