ACKNOWLEDGMENTS

This paper is dedicated to the memory of W. Downs, friend and colleague, whose spirit is always with us in the field. We thank the Authority for Research and Conservation of Cultural Heritage, the Ministry of Culture and Sports Affairs, Ethiopia, particularly Ato Jara, for permission to conduct our ongoing research in the Blue Nile Basin, the director and staff of the National Museum, Addis Ababa, for their assistance with collections, and the Gondar ARCCH and Chilga Ministry of Culture and Sports Affairs for logistical support. The project was funded by grants from the National Science Foundation EAR-0001259, the National Geographic Society, the Jacob and Frances Sanger Mossiker Chair in the Humanities, the University Research Institute of the University of Texas at Austin, to JK. BFJ, NT, AP, and JGM were supported by National Science Foundation grant EAR-0240251 to BJ, the Institute for the Study of Earth and Man at SMU, and the Downey Family Award for Faculty Excellence to BFJ and NT. Museum and field research of WJS was generously supported by a Scott Turner Award in Earth Science from the Department of Geological Sciences, University of Michigan, and funding from the Museum of Paleontology, University of Michigan. Tillehun Selassie, Misege Birara, Habtewold Habtemichael, Mesfin Mekonnen and Drs. Ambachew Kebede and Aklilou Asfaw provided valuable field assistance, and Dr. Melba Crawford and Ms. Amy Neuenschwander aided with interpretation of satellite imagery. We gratefully acknowledge help from Chilga field assistants, Yohannes Desta, Yeshiwass Sitotaw, Gebremeskel Ayele, Elias Addissu, and Teshome Yohannes. Finally, but importantly, we thank our neobotanical colleagues, John Dransfield, William Baker, Paul Wilken, and Peter Edwards, Royal Botanic Gardens, Kew.