Gurania bignoniacea and Gurania acuminata are two species of flowering vines in the cucurbit family native to tropical South America. Although each is currently considered to be a single species with widespread geographic distribution, these two names encompass more than 20 historical species epithets applied to type specimens collected across the continent.This is due to the wide variety of morphological traits exhibited by individuals within the two species complexes. Comparing these plants’ unique characteristics as described by the authors of each synonym in their original descriptive treatment shows exactly what kind of variation was judged to be indicative of unique species. Considering these comparisons spatially across the collection field also demonstrates a number of geographic patterns in the variation of morphological traits. A full and proper delineation of true phylogenetic species groups within these two complexes and the entire Gurania genus will require the use of molecular techniques previously unemployed in Gurania taxonomy. Understanding of the diversity and evolutionary history of these complexes is of greater interest than just taxonomic accuracy; these plants hold ecological importance as epiphytic exploiters of host trees, food sources for pollinating butterflies and seed dispersing bats, and hosts to an extremely diverse group of tropical fruit flies whose current ecological study is bringing into question many basic tenets of ecological theory.
Jesse Owen, ’11
Sponsor: Marty Condon