. Walla Walla, WA: US Army Corps of Engineers, Walla Walla District.
Piperno, D. R., E. Weiss, I. Holst, and D. Nadel. 2004. Processing of wild cereal grains in the Upper Paleolithic revealed by starch grain analysis. Nature 430: 670–673.
Pollan, M. 2001. The Botany of Desire. New York: Random House.
Porter, D. M. 1980. Charles Darwin’s plant collections from the voyage of the Beagle. Journal of the Society for the Bibliography of Natural History 9: 515–525.
—. 1984. Relationships of the Galapagos flora. Biological Journal of the Linnean Society 21: 243–251.
Preedy, V. R., R. R. Watson, and V. B. Patel. 2011. Nuts and Seeds in Health and Disease. London: Academic Press.
Pringle, P. 2008. The Murder of Nikolai Vavilov. New York: Simon and Schuster.
Ramsbottom, J. 1942. Recent work on germination. Nature 149: 658.
Ranker, T. A., and C. H. Haufler, eds. 2008. Biology and Evolution of Ferns and Lyophytes. Cambridge, UK: Cambridge University Press.
Raven, P. H., R. F. Evert, and S. E. Eichhorn. 1992. Biology of Plants, 5th ed. New York: Worth Publishers.
Reddy, S. N. 2009. Harvesting the landscape: Defining protohistoric plant exploitation in coastal Southern California. SCA Proceedings 22: 1–10.
Rettalack, G. J., and D. L. Dilcher. 1988. Reconstructions of selected seed ferns. Annals of the Missouri Botanical Garden 75: 1010–1057.
Riello, G. 2013. Cotton: The Fabric That Made the Modern World. Cambridge, UK: Cambridge University Press.
Rosentiel, T. N., E. E. Shortlidge, A. N. Melnychenko, J. F. Pankow, et al. 2012. Sex-specific volatile compounds influence microarthropodmediated fertilization of moss. Nature 489: 431–433.
Rothwell, G. W., and R. A. Stockey. 2008. Phylogeny and evolution of ferns: A paleontological perspective. Pp. 332–366 in T. A. Ranker and C. H. Haufler, eds., Biology and Evolution of Ferns and Lyophytes. Cambridge, UK: Cambridge University Press.
Sacks, O. 2008. Musicophilia. New York: Vintage.
Sallon, S., E. Solowey, Y. Cohen, R. Korchinsky, et al. 2008. Germination, genetics, and growth of an ancient date seed. Science 320: 1464.
Sathakopoulos, D. C. 2004. Famine and Pestilence in the Late Roman and Early Byzantine Empire. Birmingham Byzantine and Ottoman Monographs, vol. 9. Aldershot Hants, UK: Ashgate.
Scharpf, R. F. 1970. Seed viability, germination, and radicle growth of dwarf mistletoe in California. USDA Forest Service Research Paper PSW-59. Berkeley, CA: Pacific SW Forest and Range Experiment Station.
Schivelbusch, W. 1992. Tastes of Paradise: A Social History of Spices, Stimulants, and Intoxicants