Image courtesy of ARS Areawide Pest Management Research Unit.

Pollen Collection Helps Plot the Past

Archaeologists seeking clues about the life of settlers in early America are the latest experts to make use of an Agricultural Research Service special collection of more than 8,000 types of pollen. ARS scientist Gretchen D. Jones's collection of glass slides and light and scanning electron micrographs (SEMs)--a type of highly detailed photograph-- of various pollen species will be featured tonight on a Public Broadcasting Service science special. The study of pollen is called palynology.

Previously, the Smithsonian Institution in Washington, D.C., and the National Center for Ecological Analysis and Synthesis in Santa Barbara, Calif., have utilized Jones' collection of pollen, the dusty mass of tiny, yellow microspores produced by seed plants. The collection is maintained at the ARS Areawide Pest Management Research Unit (APMRU) in College Station, Texas.

The collection, started in 1988, now contains more than 8,200 types, or taxa, of pollen from the United States, Canada, Brazil, Belize and Mexico. The main emphasis of the collection is pollen taxa from Texas. Jones' collection stands out because it includes all three types of sample records--glass slides, as well as two types of micrographs. Other collections generally contain only one or two of these forms.

It's the SEMs that make Jones' collection so sought after. These photographs provide an x-ray type of image that can show minute details of something as small as a pollen grain. Pollen grain SEMs can be analyzed by archaeologists who want to learn which plants would have produced the pollen found on ancient fossils.

Today, the PBS Scientific American Frontiers program premiers its "Unearthing Secret America" episode. It focuses on archeological finds in Jamestown, and Williamsburg, Va.; and at Monticello, Thomas Jefferson's home in Charlottesville, Va. They shed light on life in early America--particularly on the origins and growth of slavery.

Portions of Jones' pollen collection will be shown in this episode to illustrate how archaeologists analyzed pollen to determine what settlers ate, what medicinal plants they used, and whether they were hunters or gatherers.

More information on the collection can be found on the Internet at:

http://pollen.usda.gov

ARS is the U.S. Department of Agriculture's chief scientific research agency.