This is a large genus of over 40 species consisting of plants with composite flowers mainly native to North America. They are perennial herbs with opposite or whorled leaves and showy clusters of small tubular flowers from which the branched style generally extends. It was named for Mithridates Eupator, King of Pontus

Note: This genus has been recently split into several different genera. Basically, the purple flowering types called Joe-Pye-Weed now belong to a separate genus, Eutrochium.