Loeselia is an obscure and little studied lineage in the flowering plant family Polemoniaceae (phlox family), which includes two genera: Loeselia L. and Dayia J.M. Porter. Despite the lack of detailed knowledge about the lineage, Loeselia has played a pivotal role in hypotheses concerning the origin of temperate members of Polemoniaceae from tropical ancestors. This research program will provide a better understanding of Loeselia (with 22 or more species). Preliminary studies of comparative DNA sequences provide evidence that Loeselia is composed of two groups of species based on ancestry, corresponding to Loeselia L. and Dayia J.M. Porter. Exhaustive taxon sampling within Loeselia and dense sampling of related groups will be used to develop an understanding of genealogical relationships (phylogeny) within and among species, using chloroplast and nuclear DNA sequences, morphological, and anatomical data.
Evidence generated through this research will lead to a new classification system and the first comprehensive monographs of Loeselia, including keys, descriptions, illustrations, distribution maps, and on-line resources. The studies of character evolution, using the same data, will provide a model for analyses of variation in reproductive traits such as self-incompatibility and floral symmetry, which is thought to be an important generator of flowering plant diversity.