Abstract
The new genus Saxiloba is described with the two species S. firmula from the Caribbean and S. hawaiiensis from Hawaii. Saxiloba is characterized by a unique, placodioid thallus forming distinct lobes, growing on rock in shaded to exposed situations with a trentepohlioid photobiont and a fenestrate thallus anatomy with distinct surface lines. The material is often sterile, but Porina-like perithecia and ascospores had previously been described for the Caribbean taxon and were here confirmed for both species. Molecular sequence data also confirmed placement of this lineage in Porinaceae. Its position within that family supports the notion that Porinaceae should be subdivided into a larger number of genera than proposed in previous classification attempts. Compared to other Porinaceae, Saxiloba exhibits a unique morphology and anatomy that recalls taxa in the related family Graphidaceae and it substantially expands the known phenotypic variation within Porinaceae. The two recognized species are similar in overall morphology but, apart from their disjunct distribution and different substrate ecology, differ in lobe configuration, color and disposition of the crystal clusters and resulting surface patterns.
Highlights
Island ecosystems exhibit high levels of endemism, often harboring unique phenotypes (Magnusson & Zahlbruckner 1945; Johnson & Raven 1973; Wagner & Funk 1995; Pax et al 1997; Morden et al 2003)
While the overall morphology and anatomy of the two lichens suggested affinities with certain Graphidaceae, in particular the genera Leucodecton and Sanguinotrema (Frisch et al 2006; Rivas Plata et al 2010; Lücking et al 2015), molecular sequence data unexpectedly placed the Cuban taxon within Porinaceae
One contained taxa with exposed, black or red perithecia, the other those with perithecia covered by thallus, except for the black-fruited Porina byssophila lineage, which clustered with support with
Summary
Island ecosystems exhibit high levels of endemism, often harboring unique phenotypes (Magnusson & Zahlbruckner 1945; Johnson & Raven 1973; Wagner & Funk 1995; Pax et al 1997; Morden et al 2003). Since the phylogenetic analysis supports the uniqueness of this lineage, it is here described as a new genus, Saxiloba. Blackfruited tropical species on leaves clustered in the genus Trichothelium, whereas temperate-subtropical species on bark and rock, including aquatic taxa, formed separate lineages (Pseudosagedia, P. pacifica clade).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
