Format: ORAL

Lacroix-Carignan, tienne*,1; Starr, Julian R.2 ; Naczi, Robert F. C. 3; Léveillé-Bourret, Étienne1

1. Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques, Université de Montréal, Montréal, Quebec, Canada. 2. Department of Biology, University of Ottawa, Ottawa, Ontario, Canada 3. New York Botanical Garden, Bronx, New York, USA

Carex subsect. Lupulinae (Cyperaceae) is a well-defined clade of four showy sedge species common in eastern North American swamps that has been the subject of no less than four independent taxonomic revisions in the last 50 years. Although these treatments were all concordant in their species delimitation, extensive fieldwork across the subsections geographic range in addition to the morphometric analysis of more than 300 herbarium specimens have revealed unexpected morphological extremes and evidence for hybrids that challenge the current circumscription of taxa. Plastid and nuclear sequences were subsequently recovered for more than 100 individuals included in morphometric analyses, and the phylogenies reconstructed from these markers were concordant with the conclusions drawn from morphology and fully support the recognition of an undescribed species endemic to the southern United States Coastal Plain. Moreover, preliminary results suggest that another cryptic species may be hidden in what is currently called Carex lupuliformis, a taxon rare throughout most of its range. The discovery of considerable morphological and molecular variation within one of the most extensively studied Carex clades in eastern North America not only demonstrates how basic studies in biodiversity continue to be relevant, but also highlights their importance to conservation in even in well-known floras.