The Poaceae are one of the most important plant families in terms of number of species, distribution, ecosystems and as food ingredient. This book results from the contributions of 150 well-known specialists and presents for the first time an in-depth look at all the viruses (including the retrotransposons) infesting this plant family. Taxonomic and agronomic descriptions of the Poaceae are presented, followed by data on molecular and biological characteristics of the viruses and descriptions to species level. Virus diseases of field grasses (barley, maize, rice, rye, sorghum, sugarcane, triticale and wheats), forage, ornamental, aromatic, wild and lawn Gramineae are largely described and illustrated (32 color plates). A detailed index of viruses and taxonomic lists will help readers in their search for information.