A couple of weeks ago I was hiking here in southeast Michigan and came across a lot of common boneset (Eupatorium perfoliatum, Asteraceae). These plants are most often found in moist and wet areas in eastern North America. I found these individuals in the wetlands of Pinckney State Recreation Area near Chelsea, Michigan.
Common boneset’s tiny white flowers grow in fragrant clusters that attract pollinators like bees and wasps. They didn’t seem as attractive to insects as the flowers of the nearby purple loosestrife, and that may be one way that invasive species outcompetes natives like boneset.
In addition to the flowers, boneset can be most readily identified by the excessively hairy stems and fused, opposite leaves. The leaves are often joined so thoroughly that they appear as one leaf with a stem piercing through.