Format: ORAL

Ryan S. Fuller1,2, Qin Li2,3,Andrew R. Hipp1,4,Jian-Quan Liu5, andRichard H. Ree1,2

1. Committee on Evolutionary Biology, University of Chicago, Chicago, IL., USA 2. Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL., USA 3. School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China 4. Center for Tree Science, The Morton Arboretum, Lisle, IL., USA 5. College of Life Sciences, Sichuan University, Chengdu, China

Understanding the evolutionary history in the genus Rhododendron (Ericaceae) is a difficult but important enterprise. The genus is iconic, both in horticulture where their charismatic flowers and hardy growth habits are highly valued, and as a prominent element of the North Temperate flora. In addition, polyploidy is highly desirable in rhododendron breeding and occurs naturally among multiple groups within the genus. The alpine group, subsection Lapponica remains somewhat of a mystery to rhody enthusiasts. While some of the species in the group display consistent morphological identity across their geographic range, many taxonomic characters hold little value for delimitation. Additionally, we have uncovered a pattern where polyploids are more frequent than previously thought. Here, we present DNA relationships among samples from China and botanical garden material that test hypotheses about species boundaries in Lapponica. In tandem, using morphological data from flowers and leaves, we compare phenotypes to one another in an effort to understand where variation is most informative for species identification. Finally, we combine the two approaches together to provide our first look at the complicated and beautiful evolutionary history of Rhododendrons Hardy Mountaineers.