Gelsemium sempervirens, commonly known as Yellow Jessamine or Carolina Jessamine, is a toxic, perennial, distylous climbing shrub indigenous to the piedmont and coastal areas of the southeastern United States. The plant produces nectar and is pollinated by species of bees, wasps, flies, and butterflies. While floral scent is known to play an important role in chemical communication between flowering plants and their pollinators, there has been little research on the floral scent composition of this native South Carolina plant known for its sweet aroma. In order to identify the sweet scent of G. semperiverens, a solid phase micro-extraction and gas chromatography-mass spectrometry (SPME-GC-MS) method was developed in 2013 and optimized to identify the volatile organic compounds present in the flower. Initial test results have revealed a number of volatile organic compounds emanating from the flowers including: benzaldehyde, p-anisaldehyde, benzyl benzoate, benzyl alcohol, and acetophenone. Verfication of the floral scent compounds in this species is underway as well as identification of the floral components that contribute to the scent profile and the nectar inhabiting microorganisms. The results of this project will provide information on the scent compounds that contribute to the specific aroma of G. sempervirens, and ultimately contribute to understanding the pollination dynamics for this species.
Math,, Science, Nursing, and Public Health, University of South Carolina Lancaster, Lancaster, SC
66 • Claudia L. Jolls, Carol Goodwillie
The Tragedy of the Uncommon: the Reproductive and Population Ecology of Rare Herbs of Forested Eastern North America
For nearly a decade, we have attempted to summarize aspects of the population and reproductive ecology of herbs, including rare species and those of forested eastern North America, particularly the southeastern US (ca. 138 taxa). We have reviewed the published primary and other technical literature using search engines such as NatureServe and Web of Science as well as comparisons of the complete understory flora at different forested sites (Harvard Forest, MA and Crabtree Creek, NC). Several themes emerge from our efforts. Most understory herbs, including the rare, are perennial, hermaphroditic, with flexible mating systems. Two distinct mating systems occur, largely outcrossing as well as predominantly selfing; obligate self- or cross-fertilization is rare. A larger proportion has partial self-incompatibility, but complete SI is rare, often accompanied by vegetative reproduction. Floral displays (size and number of flowers) as well as pollination syndromes are diverse. Most understory herbs are visited by generalist pollinators; a few have distinctive specialists. Complete, reliable quantitative data for comparative purposes are limited, making inferences and generalizations difficult. A few rare taxa are distinctive in having their ecology well-studied, including seed germination and population biology, e.g., projection matrices; population viability analyses; integral projection models; life table response experiments). Common and rare herbs are understudied with respect to what regulates population size, the stability of population sizes, site-to-site variation, and methods for propagation needed for restoration. These typically long-lived, clonal, insect-pollinated, outcrossing, and increasingly rare taxa of the understory also are acutely at risk due to fragmentation and climate change.
East Carolina University
67 • Carol Petricevic
Differences Among Populations of an Invasive Plant, Alliaria petiolata, In Germination and Growth in a Common Garden
Previous studies have shown the invasive biennial Alliaria petiolata is both phenotypically plastic and adapted to its introduced range. We conducted common garden and germination studies to further investigate this with seeds collected from populations located along the plant’s invasion route. The common garden plants were placed in plots at different elevations. The germination study seeds were placed in moist soil and cold-stratified for short, medium, and long cold stratification seasons. The results of the common garden study supported phenotypic plasticity for A. petiolata as a whole in most traits measured. Adaptation was indicated in a minority of traits, while other traits showed differences, but no patterns related to climate or range. In the germination study, most populations had near 100% germination for the long season. There were differences in germination rates for the shortened seasons, but they did not appear to be related to adaptation to cold-season length. Many differences in trait expression are likely due to genetic differences from founder effects with some possible adaptive responses; however, phenotypic plasticity is indicated for A. petiolata as a whole. This study supports the conclusion that A. petiolata is a habitat generalist.
Western Carolina University
68 • Blake W. Nelson, Andrew J. Jajack, Andrew E. Rosselot, Jay A. Yoder
Capacity of Cave Crickets to Carry Various Amounts of Fungi Depending on the Extent of Cave-Dependence: Observations Before Reports of Bat White-Nose Syndrome in the Cumberland Plateau
Cave visitors bring majority of fungi found in caves, a role played well by cave crickets (Hadenoecus) that leave and return to the cave frequently to forage that links the presence of these crickets in caves as a positive sign of a healthy cave. Mycoflora analyses and water balance experiments were conducted to examine whether different cricket species may function differently by the kinds of fungi they harbor in relation to their capacity to work effectively outside. In a north-south line of species along the Cumberland Plateau, H. cumberlandicus (Kentucky) had approximately two times more fungi on their surface than H. opilionoides (Tennessee) and H. jonesi (Alabama), with all having fairly the same fungal composition: probiotic Penicillium, Aspergillus dominating, Cladosporium, Fusarium, Mucor, Rhizopus as secondary components, and low frequency of variable components, yielding similar diversity indices. Risk of desiccation by having high water loss rate and high activation energy characterized H. opilionoides that is smaller in body size and H. jonesi that is troglomorphic-enhanced and has reduced pigmentation when compared to H. cumberlandicus that has lower water loss rates. Thus, crickets carry a large fungal load, and these fungi (mostly probiotics) are probably a method of defense against diseases, which is less important for highly cave-adapted crickets that spend more time inside the healthy cave. Nothing was recovered from cricket surfaces that resembled Pseudogymnoascusdestructans, but since our collections white-nose syndrome has appeared in this region, so whether crickets can carry P. destructans should be checked.
