People regularly use plants for a wide range of utilitarian, spiritual, pharmacological, and dietary purposes throughout the world. Scholarly understanding of the nature of these uses in prehistory is particularly limited by the poor preservation of plant resources in the archaeological record. In the last two decades, researchers in the South Pacific and in Central and South America have developed microscopic starch grain analysis, a technique for overcoming the limitations of poorly preserved plant material. In Acorns and Bitter Roots, Timothy C. Messner establishes starch grain...