Paneroa, a New Genus of Eupatorieae (Asteraceae) from Mexico

The new genus Paneroa E. E. Schilling (Asteraceae, Eupatorieae) from the Mixteca Alta region in the state of Oaxaca, Mexico, is described and illustrated, and a new combination, P. stachyofolia (B. L. Robinson) E. E. Schilling, is made. The genus is characterized by its alternate, sessile leaves. 4-ribbed phyllaries, short coroniform pappus, and clavate style appendages. Molecular phylogenetic analyses show that the genus is distinct from Ageratum L., in which the species was originally described, and is closely related to other genera including conoclinium DC, and Fleischmannia Schultz Bipontinus. It occurs in a floristic region that is characterized by numerous endemics.