Exploring the diversity of Caloplaca s. lat. lichen species in California mountain ranges

Abstract: Abstract Over 1000 published species which are largely heterogenous in morphology were formerly grouped in the lichen genus Caloplaca s. lat. (Ascomycota, eloschistaceae). Although there is no complete monograph of the genus, many taxonomic studies have focused on specific geographical regions. Although a number of these studies have focused on species that exist in California, samples of putative undescribed species were found in the mountain ranges of California. The objective of my study was to find additional samples of these undescribed species, so that I could conduct a thorough study of their taxonomy and morphology. Samples were collected in mountain ranges throughout California, the nrITS region was amplified for phylogenetic analysis, and morphological characters were measured under the microscope. Some samples came from already well known species, while some presented the first instance of their species in California. The majority of the samples belonged to two genera: Xanthocarpia and Rufoplaca. Two new species from Xanthocarpia and four from Rufoplaca are described.In general, Rufoplaca is a complicated group that needs even further research and more samples to elucidate all of the relationships. Popular science summary: Lichen hunting in California mountain ranges When people think about finding new species they often imagine that it can only be done through exploration of uncharted territory, deep in unknown corners of the rainforest. In fact, new species could still be discovered right in your backyard, if you know what you are looking for. The current study aimed to explore what lichen species grow in the mountain ranges of California, including the description and naming of several species that are new to science. Lichens are two organisms working together in symbiosis: an alga and a fungus. The algae grow inside the fungus where they harness energy from the sun that the fungus can use. The fungus, in turn, provides a safe and moist environment for the algae. The current project focused on a specific group of lichens, Caloplaca s. lat. They are most easily recognized by their orange or yellow coloration. There are already more than 1000 species published within the Caloplaca s. lat. genus, and still there are many complicated groups within the genus that should probably be split into more species. In a short trip to California, Ulf Arup found several lichens that he thought probably represented a new species. My mission was to find more specimens of these undescribed species. I traveled to four different national forests within California: Stanislaus, Yosemite, San Bernardino and Angeles National Forests, and collected all the Caloplaca s. lat. lichens that looked like they might be of interest. I took these specimens back to Lund and sequenced a region of their DNA to see how they were related to other Caloplaca s. lat. species. I also measured different morphological characteristics under the microscope. A good species should be based not only on DNA information, but should also form an identifiable group based on how they look or where they are found. New Species In total six new species were described in this project: two in the genus Xanthocarpia and four in the genus Rufoplaca. Many individuals within these groups that are currently considered a single species likely represent several species in reality, but more specimens need to be collected before we can be sure. Instead of finding additional samples of those new species previously found in California, many of the samples I found were totally new and only further complicated the situation. With each short visit to the mountains of California an abundance of new Caloplaca s. lat. species are discovered. Even a few short days in a forest are enough to turn up specimens that are new and exciting. More than anything this project shows the amount of work that is still to be done before we fully understand the Caloplaca s. lat. species that exist in California. Advisor: Ulf Arup Master´s Degree Project 30 credits in Plant Ecology and Systematics 2013 Department of Biology, Lund University