Palynology is the study of plant pollen, spores, and certain microscopic planktonic organisms (collectively termed palynomorphs) in both living and fossil form. Botanists use living pollen and spores (actuopalynology) in the study of plant relationships and evolution, while geologists may use fossil pollen and spores (paleopalynology) to study past environments, stratigraphy, historical geology, and paleontology.

The oil industry is credited with demonstrating the usefulness of palynomorphs in the study of stratigraphic sequences of rocks and the potential for oil and gas exploration. Because palynomorphs are resistant to decomposition and are produced in great abundance, their recovery from rocks and sediments via special and careful chemical treatments is possible and provides scientists with information needed to describe plant life of past ages. By describing the sequence of selected palynomorphs through the rock layers of Earth, stratigraphers (scientists who study the rock layers of Earth) are able to correlate rocks...