Background/Question/Methods: Doug Sprugel’s 1980 "pedagogical genealogy" of plant ecologists (Bull. Ecol. Soc. Amer. 61:197-200) illustrated contributions of and interactions among three major lineages of plant ecology. Its focal point was a chart outlining the influences of key professors on their PhD students and cross-influences among various schools of plant ecology as they developed. That original chart ended with students who completed degrees by 1960; they were selected to represent important schools of plant ecological thought as of 1980. With the ESA Centennial approaching in 2015, we began an update of this analysis, extending the scope of the graphical presentation through the last century and broadening its base. Although the information that can be presented in the format of a two-dimensional poster is still limited, our intent is to continue to collect information that will, with modern tools, be presented in open-ended interactive form online so that the ecological community can participate in developing a new historical resource. As with Sprugel’s genealogy, many of the interactions are unpublished, and we invite ecologists at the meeting to add comments and suggest resources and information about the "invisible colleges" that have shaped ecology.

Results/Conclusions: The original genealogy included more than 60 plant ecologists of note and illustrated the influence of the Chicago, Ohio, and Nebraska schools through the students of Cowles, Transeau, and Bessey respectively. Now expanded to include more than 100 ecologists, the chart begins to show how, and by whom, ecology has been shaped in the latter half of the 20th century. Neither the original nor the updated version could include all significant ecologists of any time period, but both suggest the interdisciplinary communication that is an important force in the evolution of our disciplines. We found that a genealogical "tree" view does not describe ecological history very effectively; there is no single trunk central to ecology. Instead the different lines interweave like W. S. Cooper’s "braided stream," and the resulting cross-fertilization often leads to very important hybrids. Much like the "n-dimensional hypervolume" of niche theory, ecological history is a tangled web that we are just beginning to portray here.