Paleobotany is the study of plant remains from geological contexts to reconstruct past environments, the evolutionary history of plants, and their bearing on the evolution of life. It includes the study of terrestrial plant fossils as well as prehistoric photosynthetic algae and seaweeds. Closely related is palynology, which studies fossilized and extant spores and pollen. Plant fossils can be preserved through impressions, petrifactions showing cellular detail, molds and casts showing three-dimensional form, authigenic mineralizations, and charcoalified fusain preserving fine morphology. Paleobotany is important for reconstructing ancient climate and ecology and the development and evolution of green plants.