This is a distinctive annual tetraploid (2n = 36), ranging widely across southeastern states but concentrated on the Coastal Plain. It is largely restricted to open areas on boggy, acid soils (FNA 25). West of the Appalachians in Ky. and Tenn., populations are mostly small and fragmented. The new genus Kellochloa differs from Pancum sensu stricto plus Coleataenia in its tuberculate versus smooth spikelets. It includes only verrucosa and brachyantha, which occurs mostly on the Gulf Coastal Plain (W and citations).