|The Whitlock lab|
|Biogeography & evolution of life histories in fringed gentians|
Closely related plant species often show differences in development that influence the morphology of mature structures and aspects of “life history,” such as the lifespan and timing of reproduction. Morphology and life history in turn influence where a plant grows - its ability to persist, disperse, and colonize new areas. We are taking a phylogenetic approach to explore the evolution of developmental morphology, life history, and biogeography in the genus Gentianopsis (Gentianaceae). This genus includes 5-25 species of wildflowers (often called “fringed gentians”) inhabiting arctic, alpine, montane, and temperate regions of the Northern hemisphere. Species of Gentianopsis exhibit previously undocumented variation in aspects of whole-plant developmental morphology, including both the pattern of shoot development and the relationship between shoot systems and root systems, that have important implications for life history. Some species of Gentianopsis are perennial, polycarpic (reproducing in multiple years), and clonal. Other species appear to be short-lived and monocarpic: they die immediately after reproduction, with little variation in patterns of development of shoot systems and no clonal growth. Gentianopsis also has complex biogeography: there is evidence for multiple radiations within North America and complex relationships among North American populations. The wide range in the number of recognized species of Gentianopsis is due to disagreements over species limits of North American taxa. The complex biogeographic relationships and morphological diversity within the genus likely have contributed to this confusion.