1. U.S. Dairy Forage Research Center, 1925 Linden Drive West, Madison, WI 53706
2. Department of Forestry, University of Wisconsin, Madison, WI 53706
3. Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108
4. Current address: Department of Chemistry, Pennsylvania State University, University Park, PA 16802
5. Current address: Department of Wood Science and Forest Products, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0346