Ephedra Pollen in Sediments of the Great Lakes Region

Ephedra spp. and Sacrobatus vermiculatus are common shrubs of dry, open sites in western North America today. Pollen of these plants has been found in surface collections in Minnesota, at high altitudes in the Rocky Mountains, and on an atmopheric slide exposed at 1,500 m over eastern Iowa. These demonstrations of long range carriage of pollen plus the fact that Ephedra pollen grains found at 13 sites in the Midwest are not restricted to the Late—Glacial but not found throughout the Postglacial sequence negate a widely held view the Ephedra was part of the periglacial flora of the Great Lakes region.