Mid- Tertiary climate of southeastern United States, the sporomorph evidence.

Climatic affinities of modern genera represented by late Eocene sporomorphs suggest that the climate of that time in southeastern United States was winter-dry tropical close to the Gulf of Mexico and marginal humid subtropical on the upper Coastal Plain. Lack of change of the sporomorph assemblages suggests that the climate of southeastern United States did not change appreciably from late in the middle Eocene until nearly the end of the Eocene. Then the climate rapidly became cooler and perhaps drier, a regime that persisted into the early Oligocene. -Author