Starch Grain Analysis

Starch grain analysis recovers and identifies microscopic starch granules preserved on archaeological artifacts and in dental calculus to reconstruct ancient plant use. Many economically important plants — tubers, roots, seeds, and cereals — store energy as starch in granules whose size, shape, hilum position, and surface features can be diagnostic of a plant family, genus, or even species. Because starch can lodge in the use-wear pits of grinding stones, adhere to pottery, settle into sediments, and become trapped in calcified dental plaque, it survives where charred macroremains do not, opening a window onto plants such as manioc, potato, and banana that rarely carbonize. Under polarized light, intact starch shows a characteristic birefringent extinction cross, and identification proceeds by morphometric comparison to modern reference granules, following procedures consolidated in Pearsall's paleoethnobotanical handbook.