A new species of Polymnia (Compositae: Heliantheae) from Mexico

Polymnia mcvaughii from Jalisco, Mexico, is described as new. This herbaceous species appears to belong in the mainstream of evolution within the genus. It exhibits marked affinities to several species, but most closely resemblesP. oaxacana Schultz-Bip. Illustrations of important features are included, along with a list of key characteristics.