Volume 25 of Flora North America is one of two volumes on grasses to be published in this series. Together they will provide a comprehensive, authoritative, illustrated account of this important group of plants. Most of the species treated are either native to North America north of Mexico or are introduced species that are now established in the region, but there are many that do not fit into these categories. Among the additional species are several that the USDA has identified as major weed threats; and others that are known only as cultivated plants, some being cultivated for their...