Two new species belonging to the common and widespread lichen genus Physcia are described from western North America. One of these, P. occidentalis, is an obligately saxicolous species that reproduces by fragmentation, primarily through the production of largely terminal blastidia. Only a single very immature apothecium was observed among all collections. The species occurs from British Columbia to California, with outliers in Colorado. The other species, P. rhizinata, is a corticolous, typically fertile species lacking asexual propagules, and has often been confused with P. stellaris. It is presently known only from California. The close evolutionary relationship of these morphologically dissimilar taxa highlights the currently limited understanding of factors that lead to phenotypic divergence in lichen symbioses.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 123 • No. 2