Barkworth Grasses are the world's most important plant group. They provide over 70% of the calories humans consume, either directly as cereals or indirectly as forage. They grow in almost any habitat that supports plants, and were once the dominant species over large parts of North America. Despite this importance, there has never been a comprehensive guide to the grasses of North America. The best available account covers only the lower 48 states and dates from 1951. The lack of a current treatment for the whole of North America is a major problem for workers in many different fields, including ecology, land management, horticulture, weed control, and plant systematics because all depend on accurate identification of the plants involved. An additional need is for clear line drawings that show the distinguishing features of individual grass species because grasses do not have the conspicuous floral features that are used to identify most other flowering plants. The project by Dr. Mary Barkworth will complete the publication of the second, final volume on grasses that will provide, for the first time, a fully illustrated account of the grasses of North America. The volumes reflect the collaborative efforts of literally hundreds of taxonomists; this number includes over 70 contributors and an even larger number who have reviewed individual treatments, provided the information needed to generate detailed distribution maps, and answered questions. In addition, many herbaria, including overseas herbaria, have provided files of distributional information and/or loaned specimens for illustration. An editorial team at Utah State University is responsible for ensuring consistency, both among the treatments and between the identification keys and the descriptions, and for checking that the illustrations complement the identification keys. In addition, they developed the indices that enable the account of individual species to be located using either a common name or a scientific name, and two bibliographic references, one listing published sources of information used in preparing the distribution maps and another listing all the literature citations contained in the volume. These two grass volumes will provide an unparalleled resource for those seeking to identify grasses. Although designed for use within North America, the volumes will be of value throughout the world because the species treated include all species native to North America north of Mexico, all the introduced species that are now established in this region, and several species that, so far as North America is concerned, are known only in cultivation, some for food, some for recreational use (such as golf greens and football fields), and some as ornamentals. In addition, the volumes include all the grass species that the USDA has identified as potential weed threats to U.S. agriculture, whether or not they have yet been found in North America. The primary emphasis of this project is on completion of the print volumes but, as material becomes available, it is posted to the Web, so that it can be incorporated into educational materials for use in both formal and informal settings.
