To evaluate the importance of morphological and chemical characters used in the recognition of species within the Parmelia omphalodes group, we performed phylogenetic, morphological and chemical analyses of 335 specimens, of which 34 were used for molecular analyses. Phylogenetic analyses, based on ITS rDNA sequences, show that P. pinnatifida is distinct from P. omphalodes and the most important difference between those species is the development of pseudocyphellae. In P. pinnatifida, they are mostly marginal and form white rims along lobes margins, but laminal pseudocyphellae can develop in older parts of thalli and are predominantly connected with marginal pseudocyphellae. In contrast, in P. omphalodes laminal pseudocyphellae are common and are predominantly not connected to marginal pseudocyphellae. Chemical composition of secondary lichen metabolites in both analysed species is identical and therefore this feature is not diagnostic in species recognition. Few samples of P. discordans, species morphologically similar to P. omphalodes and P. pinnatifida, were also included in the analyses and they are nested within the clade of P. omphalodes, despite the different chemistry (protocetraric acid present versus salazinic acid in P. omphalodes). All taxa of the P. omphalodes group occupy similar niches, but their potential distributions are wider than those currently known. The absence of specimens in some localities may be limited by the photobiont availability. Parmelia omphalodes and P. pinnatifida are moderately selective in photobiont choice as they form associations with at least two or three lineages of Trebouxia clade S. Parmelia pinnatifida, as well as P. discordans are associated with Trebouxia OTU S02 which seems to have a broad ecological amplitude. Other lineages of Trebouxia seem to be rarer, especially Trebouxia sp. OTU S04, which is sometimes present in P. pinnatifida. This study indicates the importance of extensive research including morphology, chemistry and analysis of molecular markers of both bionts in taxonomical studies of lichens.

To test the taxonomic significance of secondary chemistry (particularly lobaric acid and fatty acids) and pruina in Parmelia ernstiae, P. saxatilis, P. serrana, P. submontana and P. sulcata in Europe, 3684 specimens were analysed morphologically and chemically, and 82 ITS rDNA sequences were prepared. A comparison of the resulting phylogram with the production of secondary metabolites (P. saxatilis group) and the intensity and presence of the thallus pruina (all five species) show that lobaric acid occurs in only three species, P. ernstiae, P. saxatilis and P. serrana, but its presence is variable within them. Fatty acids are restricted to P. ernstiae and P. serrana. All studied species can develop epruinose to strongly pruinose thalli, and therefore pruina is an uninformative character at species level. The traits reliable for the determination of the species are the type of vegetative propagules, their placement on the thallus, and the lobe shape. It was previously suggested that the development of pruina may depend on light intensity, but epruinose and pruinose thalli of the same species were often found growing side by side in exactly the same environmental conditions. Thalli differing in pruina intensity might contain different photobiont strains.

The first records of Sticta weigelii s.str. from Bolivia confirmed by molecular data are presented. The species is characterized by the presence of marginal isidia, which are darker than the thallus, usually cylindrical (not flattened), thin, dark brown to black lower tomentum and often partly yellow cyphellae. Previously, the presence of S. weigelii in Bolivia was based only on a morphological concept, encompassing various unrelated species, whereas the occurrence of S. weigelii s.str. was uncertain.

No abstract

Six species of Sticta are described as new to science on the basis of material from Bolivia and supported by phylogenetic analysis of the fungal ITS barcoding marker. The species were resolved in all three of the clades (I, II, III) widespread and common in the Neotropics, as defined in an earlier study on the genus. Comparison with material from neighbouring countries (i.e. Colombia, Ecuador, Peru) suggests that these new species may be potentially endemic to the Bolivian Yungas ecoregion. For each species, a detailed morphological and anatomical description is given. Sticta amboroensis Ossowska, Kukwa, B. Moncada & Lücking is a medium-sized green-algal species with laminal to submarginal apothecia with hirsute margins and with light to dark brown lower tomentum. Sticta aymara Ossowska, Kukwa, B. Moncada, Flakus, Rodriguez-Flakus & Lücking is a comparatively small cyanobacterial taxon with Nostoc as photobiont, laminal, richly branched, aggregate isidia and a golden to chocolate-brown lower tomentum. The medium-sized, cyanobacterial S. bicellulata Ossowska, Kukwa, B. Moncada & Lücking has cyanobacterial photobiont, bicellular ascospores, apothecia with white to golden-brown hairs on the margins, K+ violet apothecial margin (ring around disc) and epihymenium and a white to dark brown lower tomentum. In contrast, the green-algal species, S. carrascoensis Ossowska, Kukwa, B. Moncada & Lücking is characterised by its large size, apothecia with dark brown hairs on the margins and a yellow medulla. The cyanobacterial S. catharinae Ossowska, B. Moncada, Kukwa, Flakus, Rodriguez-Flakus & Lücking forms stipitate thalli with Nostoc as photobiont, abundant, laminal to submarginal apothecia and a golden-brown lower tomentum. Finally, the cyanobacterial S. pseudoimpressula Ossowska, Kukwa, B. Moncada & Lücking produces laminal apothecia with an orange-yellow line of pruina along the margins which reacts K+ carmine-red. In addition to the six new Bolivian taxa, the cyanobacterial S. narinioana B. Moncada, Ossowska & Lücking is described as new from Colombia and it represents the closely-related sister species of the Bolivian S. aymara; it differs from the latter largely in the marginal instead of laminal isidia.