Robert H. Mohlenbrock is Distinguished Professor Emeritus at Southern Illinois University, Carbondale, and Senior Scientist at Biotic Consultants, Inc. Among his many books are "You Can Grow Tropical Fruit Trees "(1999), "Field Guide to North American Trees "(1987), "Field Guide to North American Wildflowers "(1987), and "Where Have All the Wildflowers Gone? "(1983). Mike Dombeck is Chief Emeritus of the U.S. Forest Service.