Archaeobotany and the Development of an Eastern North American Starch Grain Reference Collection.

In the last several decades the study of prehistoric people and plant interactions in Central and South America, as well as the South Pacific, has been revolutionized by the utilization of plant microfossil (phytolith and starch grains) analyses. This is primarily due to their depositional intensity combined with a resilient physio-chemical composition that withstands deleterious climatic conditions enabling their recovery from archaeological contexts poorly suited to macrobotanical preservation. Recent starch grain analysis studies conducted in North America have demonstrated the utility of this methodology for reevaluating our understanding of prehistoric plant use in temperate regions. In order to utilize this line of archaeobotanical inquiry to its fullest potential however – e.g. secure the taxonomic identity of archaeological residues – the range of morphological variability present within a specific geographic area must first be understood. Using ethnohistoric and ethnobotanical studies conducted throughout eastern North America, a list of plant resources reportedly utilized for dietary and medicinal purposes was generated and used as the basis for developing the regions first starch grain comparative collection. With the help of the Plant Genetic Resources Conservation Unit, the largest known collection of propagules composing these economic and closely related taxa has been assembled and analyzed. This paper reports on the taxonomic value of starch produced by this genetic material and its utility in advancing our archaeological understanding of people and plant interactions in eastern North America.