Boraginaceae, one of the largest families of the Lamiids, is characterized by a scorpioid cyme, gynobasic style, and nutlets. Although these features in the family are constant, others, including leaf venation, corolla shape, herkogamy, and nutlet ornamentation, are quite variable. Consequently, the family provides in an interesting group to study questions concerning the evolution of various morphological features. In order to address these questions in a phylogenetic context, my students and I are working to create a matrix that includes DNA regions from the three plant genomes as well as morphological characters. The phylogeny derived from this matrix will inform our understanding of evolutionary relationships, character evolution, development, and taxonomy.
Heterostyly Evolution and Development
Heterostyly, a complex and elegant breeding system, is defined as the occurrence in a species of two or more floral morphs that exhibit reciprocal herkogamy. Heterostyly is often associated with ancillary physiological and structural characters, such as self- and intramorph-incompatibility (SI) and pollen and stigma polymorphisms. The breeding system has evolved multiple times among the angiosperms, but we are still trying to understand the manner in which heterostyly can arise and how heterostyly differs in each origin. My students and I are studying floral developmental patterns of heterostyly and placing these data in an evolutionary context in order to better understand the origin of this breeding system.
Plant diversity and abundance varies throughout the world. In some areas, plant diversity is threatened, and this is particularly problematic for rare plants. Conservation efforts are undertaken to protect these species in order to preserve biodiversity for future generations of humans and ecosystems. Two plant species that are a focus of conservation efforts are Oreocarya crassipes, the Terlingua Creek Cat's-Eye, and Phlox hirsuta, the Yreka Phlox. Both of these species have limited geographic distributions and may be threatened by increasing development, so understanding their population structure and breeding system is important in order to help better conserve them. Using a combination of field and molecular biology techniques, colleagues, students, and I are working to ensure that these species will be able to continue to survive in their native habitats.