Tropical Biology Section
Benavides, Juan C. , Crandall-Stotler, Barbara , Stotler, Ray .
Fossombronia peruviana and Allied Species in Latin America - A Systematic Puzzle.
The northern Andean Fossombronia peruviana Gottsche & Hampe is the only Latin American taxon included by Schuster in the genus Austrofossombronia R. M. Schust. This segregate was differentiated from Fossombronia by large plant size, elongate rather than spheroidal capsules, capsule walls 3 or more cell layers in thickness, and its unique wetland habitat. In molecular phylogenies the species of Austrofossombronia have been resolved in multiple clades of Fossombronia, providing little justification for its recognition. Our recent expanded molecular analyses, coupled with comprehensive studies of living and herbarium specimens from throughout the Andean chain provide evidence for the recognition of more than one species in the F. peruviana clade. Populations that are morphologically referable to F. peruviana are widely distributed in wet, high elevation sites from Venezuela to Bolivia. Within the range of F. peruviana, we have discovered a second, as yet undescribed, genetically distinct sister species from several localities in Venezuela, which is, in turn, closely related to a third morphologically distinct element from Toluca Volcano, Mexico. Both gametophyte and sporophyte characters clearly differentiate the Mexican element from F. peruviana, and the Venezuelan element differs from both F. peruviana and the Mexican population in leaf insertion and antheridial anatomy. In the absence of female plants and sporophytes from the Venezuelan element, however, its relationship to the Mexican population is equivocal. A single collection of a similar, large Fossombronia made by J. B. Hatcher in Feugia, which was identified as F. naumannii Schiffn. by Evans (1898. Bull. Torrey Bot. Club 25: 415), is not referable to that species, but appears to be, on the basis of morphology, aligned with the Venezuelan element. Although combined molecular and morphological data provide indisputable evidence of species level divergence between F. peruviana and allied elements in Mexico, Venezuela and Fuegia, determining how the latter are related to each other requires more extensive sampling of high elevation Fossombronias along the Cordilleras of Latin America.
1 - Southern Illinois University, Department of Plant Biology, 1125 Lincoln Dr, LSII Bld Room 420, Carbondale, IL, 62, USA
2 - Southern Illinois University, Department Of Plant Biology, 1125 Lincoln Avenue, CARBONDALE, IL, 62901-6509, USA
3 - Southern Illinois University, Department Of Plant Biology, 1125 Lincoln Drive, CARBONDALE, IL, 62901-6509, USA