Each flower has a fused white to pale yellow four-lobed corolla forming a long slender tube connecting to the sepals.

[4] There are two varieties, not considered distinct by all authorities: Buttonbush is a common shrub of many wetland habitats in its range, including swamps, floodplains, mangrove, pocosin, riparian zones, and moist forest understory.

In Canada, it occurs from southern Ontario and Quebec east to New Brunswick and south-western Nova Scotia.

Besides the eastern United States, and eastern regions of the Midwest, notable areas range into Arizona, the Mogollon Rim, and other mountain ranges; in California, the entire San Joaquin Valley[10] West of the Great Plains and the Rocky Mountains, only western Texas, Arizona, and California find C. occidentalis.

A lone buttonbush served as a landmark on an old trans-San Joaquin Valley trail, and was used by ancient Yokuts as a meeting place.