Buttonbush (Cephalanthus occidentalis) is native to most of the continental United States, often occurring in wetlands or along streams, though it can be grown just about anywhere with not-too-dry soil and full sun or partial shade. It blooms for several weeks in summer and attracts a plethora of pollinators; you can see several tiny, unidentified critters along with the honey bee in this photo.
Diane Makovec refers to this as the “Horton Hears a Who” bush, due to its distinctive pincushion flower heads. And indeed, photographer Nicholas May said he was camping on the Courtois Creek in southern Missouri’s Huzzah Valley when he ran across these “Dr. Seuss-like flowers” with bees all over them.