Eupatorium serotinum, also known as late boneset or late thoroughwort, is a fall-blooming herbaceous plant native to North America. Eupatorium serotinum ranges throughout most of the eastern United States, found in every coastal state from Massachusetts to Texas and inland as far as Minnesota and Nebraska. There are reports of one small population in the Canadian Province of Ontario, and other reports of the species on the south side of the Río Grande in northern Mexico.