Chemotypic Variation of Conocephalum salebrosum in the Southeastern Appalachian Range: A Search for Cryptic Plant Biodiversity Around the Tennessee River Valley

Abstract

The chemotaxonomy of the Conocephalum spp. complex, based on GC-MS analysis of the volatile compositions, has helped to reveal cryptic biodiversity and delineate actual distribution patterns of chemotypes. In the Appalachian Mountains, two samples from eastern central part of the range were previously shown to be C. salebrosum. Additionally, it has recently come to light that stress can alter the volatile composition of C. conicum. This study address a previously unsampled region of the southeastern Appalachians, a region that is a biodiversity epicenter, to determine if more chemotypic diversity remains to be seen for the Conocephalum spp. complex. A common garden experiment was performed, but yielded more of a common stress experiment, and significantly altered the volatile compositions. Wild-collected controls and a meta-analysis of these data and those from previous works suggest that the common garden experiment caused stress and that the liverworts sampled belong to the C. salebrosum clade of of the Conocephalum spp. complex.