A considerable amount of study material has beccme available since the revision of the genus in 1900 by Shear, and the revision of the section Bromopsis in 1952 by Wagnon. A number of cytological studies have been done in recent years; and Wagnon's work pointed out the need for a comprehensive study of the entire genus. This study is a taxonomic revision of the Genus Bromus for the State of Utah, and contains illustrations and descriptions of the species; synonomy; distribution maps; and discussions of many of the important aspects of the economics, ecology, and historical treatment. I have recognized 17 species and 2 varieties as being present in the State, and these, along with another 4 closely allied or formerly cited species or varieties reported for Utah, are separated by means of a comprehensive dichotomous key based on the natural grouping of these grasses into sections within the genus. Much of the research has been based on herbarium study of the morphological variation for the separation of taxa, and was supplemented with extensive field observation and collection during the past decade.