The enormous trees forming rainforest canopies bear little resemblance to their seedlings, many described for the first time in the new field guide, "Seedlings of Barro Colorado Island and the Neotropics," published in July 2009 by Cornell University Press. Author Nancy Garwood, professor of plant biology at the University of Southern Illinois in Carbondale, began the daunting task of describing seedling stages of tropical plants 25 years ago at the Smithsonian Tropical Research Institute in Panama.