This project studies plants with foul-smelling red flowers that bloom in early spring in the southeastern U.S.A. These plants are intriguing because they appear to be sending the same floral message to pollinators. This looks like a floral syndrome (where unrelated plants converge on a common appearance or odor to lure the same, specific pollinators) BUT something is amiss: these flowers attract as pollinators a guild of generalized insects that feed on decaying organic matter. Documenting blooming patterns, visitors, and floral characteristics in populations across three southeastern states will characterize this apparent syndrome. This project impacts undergraduates who will perform all stages of science for academic credit. Students will read relevant literature and design experiments, set out field plots, collect and analyze their data. The following spring, students will present their results at the Association for Southeastern Biologists? annual meeting and submit them for publication. This project initiates the Wine Guild Curriculum Partnership with the GSU Botanical Garden that will impact several thousand K-12 school children and their teachers. This outdoor curriculum provides hands-on experience with pollination biology. The children will run essentially the same experiments at the Botanical Garden that investigators run in the field, providing first-hand experience with the scientific process and a greater appreciation for this rich floral heritage.
One of the primary challenges in modern biology is to evaluate whether the patterns that emerge through intensive study of any group of organisms (their morphology, behavior, genetic diversity, etc.) can be interpreted to reveal the processes responsible for generating those patterns. For example, botanists have long debated whether floral color, shape and scent are predictive of the kinds of animals that pollinate such flowers, implying that pollinators are the primary selective agents on floral evolution. More recent studies suggest that floral diversification is shaped not only by pollinators, but by natural enemies and abiotic conditions as well. Furthermore, recent studies have questioned whether pollinators really serve as specialized selective agents, arguing that most plants vary between years and sites in terms of which animals pollinate them. If "generalized" pollination predominates, flowers should rarely show evidence of specialization. The intellectual merits of this project stem from its unbiased experimental approach to studying the paradox of specialized flowers with generalized pollination. We studied a guild of plants whose flowers have unusual qualities: they are wine-red in color, smell like fermenting fruit or yeast, offer no nectar and bloom in early spring across the coastal plain of eastern North America. We studied several replicate species (red vs. white flowered Trillium, Calycanthus, Illicium and Asimina) in NY, NC, GA and FL, measuring pollinator visitation, herbivory, seed production and clonal propagation, floral temperature and exposure to ultraviolet radiation. The "wine red" flowers are visited by a diverse guild of insects – several families of flies and beetles – that don’t normally visit flowers, but instead are attracted to rotting fruit, sap and yeast. However, fruit production is rare, suggesting that pollination is not always successful. Sticky traps baited with flowers or yeast effectively trapped these insects regardless of trap color, suggesting that red pigment is not a pollinator attractant. Similarly, red colored flowers did not differ in floral temperature from white colored relatives in the same setting, nor were they an artifact of plants with more reddish foliage. However, red-flowered species bloomed one to two weeks before the closure of the forest canopy due to springtime leaf expansion, whereas white flowered relatives bloomed during or after canopy closure, when incident ultraviolet radiation was much lower. Furthermore, most red-flowered species can propagate clonally, thus the plants do not depend solely on pollination. We conclude that the ecological niche of these plants (early spring bloom in moist forest understory), with its attendant abiotic conditions (cold, rainy weather, high ultraviolet incidence) has shaped patterns in floral biology in tandem with floral attraction of unusual pollinators (flies and beetles) abundant during early spring. The broader impacts of this project focus on two educational activities that were integrated into the scientific study and were carried out in the primary locations for our research. The first, led by co-PI Amy Boyd (Warren Wilson College, NC), was an undergraduate course designed to guide six students through the entire process of biological research. The students were selected from a pool of applicants through an interview process, and began the semester researching the background concepts relevant to floral pollination, ecological guilds and pollinator mediated selection. From this early stage of planning, they learned experimental design and elementary statistics, went to the field sites (near Asheville, NC) to lay out experimental plots, then worked in teams to collect, analyze and interpret field data (as described above) for Trillium and Calycanthus plants as the semester ended. The students created a web log (http://redflowerproject.blogspot.com/2010/10/living-fossils.html ), which they used to communicate their observations and ask questions of the other project co-PIs. The students finished the course by presenting their data in a mini symposium attended by all project participants, and then presented their results publically at the annual meeting of the Association of Southeastern Biologists (www.sebiologists.org/) . The second activity was to coordinate a "living fossils" exhibit with the education staff of the Georgia Southern University Botanical Garden, located in the heart of "wine-red" (http://academics.georgiasouthern.edu/garden/) flower habitat. With the exception of trilliums, all of our focal plant groups in this project represent ancient lineages of flowering plants, noteworthy for their shared distributions between southeastern North America and east Asia, a distribution common to such "living fossils" as magnolias and swamp cypresses, iconic trees of this region. The garden already features several plantings of native, red-flowered pawpaw (Asimina triloba), sweetshrub (Calycanthus floridus) and star anise (Illicium floridanum) on the grounds, and acquired white flowered relatives (Sinocalycanthus chinensis and Illicium anisatum) native to Asia, to plant alongside them. Co-PIs worked with the garden director and education coordinator to design teaching modules for local school teachers to use during class visits to the gardens. Students will be able to watch red and white flowered relatives side by side and compare differences in pollinator visitation, floral morphology and scent themselves.
