Manual of Grasses for North America. Mary E. Barkworth, Laurel K. Anderton, Kathleen M. Capels, Sandy Long, and Michael B. Piep (eds.). 2007. Utah State University Press, Ogden, UT 84322. 640 p., 900 illustrations and maps. $89.95, paperback. ISBN-10: 0874216869, ISBN-13: 978-0874216868.
Students and researchers throughout the United States revere the Manual of Grasses of the United States (Hitchcock, A.S. 1951. 2nd ed., revised. A. Chase. USDA Misc. Publ. 200. U.S. Government Printing Office, Washington, DC), although it may be long out of date. Mary Barkworth and colleagues at Utah State Intermoutain Herbarium have changed this situation with the recent publication of Manual of Grasses for North America from Utah State University Press.
The scope and purpose of the book are stated on the cover: “The Manual of Grasses for North America is designed as a successor to the classic volume by Hitchcock and Chase. It reflects current taxonomic thought and includes keys, illustrations, and distribution maps for the nearly 900 native and 400 introduced species that have been found in North America north of Mexico. In addition, it presents keys and illustrations for several species that are known only in cultivation or are of major agricultural significance, either as progenitors of bread wheat and corn or as a major threat to North American agriculture because of their ability to hybridize with crop species.”
Information contained in the Manual of Grasses for North America was first published as two volumes of Flora of North America (Flora of North America Editorial Committee, M.E. Barkworth et al. (eds.), 2007. Flora of North America North of Mexico, Parts 1 and 2, Vol. 24 and 25. Oxford University Press, New York). These two volumes cover Poaceae in North America north of Mexico. In addition to native species and established introductions, they include many cultivated grass species, some introductions that failed to become established, and a few weedy species not known from the region but identified by the USDA as potential threats to U.S. agriculture.
The Manual of Grasses for North America reduces the content of the two-volume Flora of North America to a single book that includes descriptions for the tribes and genera plus all the keys, illustrations, and maps in the original two-volume edition. Subfamilies and species description (except habitat information) have been eliminated in the condensed new Manual of Grasses for North America, and illustrations are reduced to one-quarter of their original size. This condensed volume, the authors state, “is hoped, will prove as useful to today's taxonomists as the Hitchcock's Manual of Grasses of the United States used to be.”
A hefty tome at 4.4 pounds, the Manual of Grasses for North America is divided into three sections: 346 pages of taxonomic treatments including keys to tribes, genera, and species; 155 pages of illustrations with detailed floral and plant diagrams; and 51 pages of species distribution maps. With detailed indices, the book is easy to use, and locating a particular species within each of the three sections is accomplished quite quickly. Citations are abbreviated in the Manual of Grasses for North America, so for complete information one needs to look online http://utc.usu.edu/grassbib.htm and refer to the two-volume Flora.
Many new, cultivated, and escaped grasses are listed. For example, Pennisetum setacuem ‘Rubrum’, a popular ornamental grass, is now classified as Pennisteum advena with “origin uncertain.” Calamagrostis acutiflora ‘Karl Forester’ is listed as a European hybrid of C. arundinaceae and C. epigejos.
The USDA Plants Database (http://plants.usda.gov/) has become a standard reference for nomenclature and plant information with the advantage of being constantly updated and available online. Information in the Manual of Grasses for North America is integrated into the Plants Database, so when searching for Elymus hystrix, for example, in the Plants Database, you will find species description, illustrations, and distribution maps from the Manual of Grasses for North America (referred to in the Plants Database as the Grass Manual on the Web). This procedure is actually the best way to find the online information; since the Manual of Grasses for North America website itself (http://herbarium.usu.edu/webmanual/) has limited information, more links are available through the Plants Database.
Students, teachers, and research scientists will enjoy having an up-to-date reference that provides good keys and taxonomic differences for Poaceae throughout the United States. For anyone seeking further detail, consulting the two volumes of the Flora can easily be done at most university libraries. Barkworth and her colleagues have produced a welcome addition for grass identification and classification.
