The Late Cretaceous and Early Tertiary periods are critical times in the history of the flowering plants. Information about evolutionary changes during this period has come from the study of leaves, pollen, and most recently, flowers, fruits, and seeds. Although fossil, petrified woods of flowering plants occur throughout deposits in the United States, there have been few systematic studies of their anatomy. Dr. Elisabeth Wheeler of North Carolina State University will study the anatomy and taxonomic relationships of several collections of Cretaceous and Tertiary woods, to extend our understanding of the history of particular plant groups. Data on the structural characteristics of the woods examined during the study and data from the literature will be organized into a computer database. Changes in wood structure through time will be tracked, and compared with changes in other plant parts. The success of this project is dependent to a large degree on access to a database with information on the wood anatomy of a large number of living species. Such a database has been established at North Carolina State and will be expanded. This expansion will facilitate the comparison of fossil woods to extant plants, and will be of benefit to anyone needing to identify wood samples of both living and fossil plants.