Putting Archaeobotany Under the Microscope: A Case Study for Increased Use of Starch-Grain Residue Analysis on the North Coast of Peru

Due to the arid environment and subsequent excellent preservation on the north coast of Peru, evidence obtained from macrobotanical remains here has been the primary sources of information on plant use. However, despite the richness of the macrobotanical record, the combination of arid conditions and the nature of many plants, such as potatoes and beans – which are consumed in their entirety – macrobotanical remains can only tell us so much. In this paper, we discuss some methodological issues in north coast Peruvian archaeobotany, specifically the over-reliance on macrobotanical analyses and the relative under-use of starch grain residue analysis. We discuss starch grain evidence from Wasi Huachuma, a Late Moche site in the Jequetepeque Valley, including traces of potato from a grinding stone and a cooking pot. Prior to this, no physical evidence of potato had been recovered from Moche contexts despite Moche iconography featuring potatoes. This indicates that macrobotanical analyses alone are insufficient for uncovering the spectrum of foodstuffs utilized by the Moche. We argue for a more rigorous and consistent application of starch grain residue analyses, in order to obtain as much information as possible about past plant utilization, rather than relying on macrobotanical remains alone.