OP VI, Unit 9, Layer 1, Feature 1. Sample listed as "corn" (Haas et al. 2013:Table S1).
Haas, Jonathan, Winifred Creamer, Luis Huamán Mesía, David Goldstein, Karl Reinhard and Cindy Vergel Rodríguez 2013 Evidence for Maize (Zea mays) in the Late Archaic (3000-1800 B.C.) in the Norte Chico Region of Peru. PNAS Early Edition:1-5.