1. This research was supported by National Geographic Society Grant 4816-92. We gratefully
acknowledge the work of B.-E. van Wyk, Rand Afrikaans University, Johannesburg, who
provided the analyses of sugar nectars. We also thank Peter Bernhardt, Dee Paterson-Jones, and
Kim Steiner for helpful comments during the preparation of this paper.
2. Compton Herbarium, National Botanical Institute, Private Bag X7, Claremont 7735, South
Africa.
3. B. A. Krukoff Curator of African Botany, Missouri Botanical Garden, P. O. Box 299, St.
Louis, Missouri 63166-0229, U.S.A.