Common Weeds of the United States describes and illustrates over 200 of the most common or problematic weeds -- both native and introduced -- found across the United States. In any situation where weed control is necessary, it is first necessary to correctly identify the plant species. It is for this purpose that this guide has been prepared, and the intended users are research workers, weed specialists, agricultural extension agents, gardeners, farmers, park managers, and others interested in weeds and their control. Originally published in 1970, this new edition has been updated to reflect the many taxonomic changes in both family assignments and in genus and species names. The guide has been completely reformatted for easier use, with plants presented in alphabetical order by plant family. Detailed illustrations by preeminent botanical illustrator Regina Olson Hughes depict both the overall plant as well as its flowers, fruits, and seeds. Nearly 500 full-color photographs have been added to highlight key features of each plant. Finally, county-level distribution maps are provided to help narrow the range of possible weed species.