Analysis of maize (Zea mays subsp. mays) pollen: Normalizing the effects of microscope‐slide mounting media on diameter determinations

Abstract

Maize (Zea mays subsp. mays) dominates the record of prehistoric agriculture in the Neotropics. Nonetheless, many significant questions of Zea systematics and evolution persist. Palynology provides a record central to addressing those questions, but determining pollen grain diameter remains a significant methodological issue: diameter is a key characteristic in identification, and diameter seems to be space‐time dependent — the latter phenomenon but little understood. One issue in analyzing diameter is the confounding effect of microscope‐slide mounting media. This study provides correction factors to normalize diameter among silicon oil, glycerine jelly, and acrylic resin (du Pont Elvacite), the last coming into increasing use without previous study of its effect on pollen grain size.