Search

As part of our ongoing research on Peltigera, we recognize a morphologically and phylogenetically distinct new species, Peltigera shennongjiana L. F. Han & S. Y. Guo, from the Shennongjia region of Central China. It is distinguished from other members of the P. canina-group by the presence of abundant phyllidia and flat, branched lobules along the margin or laminal cracks, short lobes, and a pruinose, usually greyish upper surface. The various populations sampled share identical ITS nr DNA sequences, of which the ITS2 regions are characterized by a unique secondary structure. Furthermore, we provide a detailed comparison of the characteristics of P. shennongjiana with morphologically similar species and a key to Peltigera species reported from China.

Fuscopannaria leucostictais a rare and understudied cyanolichen with an interesting and unusual distribution in tertiary relict hotspots worldwide. There is a relatively large population in eastern North America, where it occurs mostly throughout the Appalachian Mountains and reaches its northernmost extent in New Brunswick and Nova Scotia, Canada. The ability to detect this species, and thus determine its habitat requirements, is critical for understanding how it might be affected by human-induced environmental degradation. Maximum entropy modelling with MaxEnt was used to predict the distribution of suitable habitat for this species in Nova Scotia using 62 presence locations, 1405 pseudo-absence locations and four environmental covariates: depth to water table (a proxy for relative soil moisture), distance to the coast and mean annual temperature and precipitation. Our predictive maps identify important habitat features and areas of high suitability in Nova Scotia with an area under the curve value of 0·85. The predicted distribution of this lichen was most affected by temperature. This study elucidates locations as well as species-habitat relationships forF. leucosticta,providing land managers with baseline data that can aid in the discovery of additional populations and provide a better understanding of its ecological requirements which will support the development of sound conservation strategies for this rare lichen.

During lichenological explorations of tropical montane forests in Kenya, a remarkable new lichenicolous fungus was repeatedly found growing on thalli of the epiphytic tripartite cyanolichen Crocodia cf. clathrata. Molecular phylogenetic analyses placed the fungus within Gomphillaceae (Ostropales, Lecanoromycetes), a family mainly of lichen-symbiotic species in the tropics. The anatomical features (unitunicate, non-amyloid asci and simple, septate paraphyses) as well as the hemiangiocarpic ascoma development confirm its taxonomic affinity. DNA sequence data showed the closest relationship was with Gyalidea fritzei, followed by Corticifraga peltigerae. A monotypic genus, Taitaia, is introduced to incorporate a single species, T. aurea. The new fungus is characterized by aggregated ascomata with yellow margins and salmon red discs developing from a single base.

A new cyanolichen,Peltigera islandicasp. nov. in the sectionPeltigera(‘P. caninagroup’) is described from Iceland. This species is similar in general appearance toP. rufescensandP. membranacea, but may be recognized by its downturned lobe tips and narrow lobes, respectively. Most thalli are bright emerald green in colour when moist, although a dark khaki green colourmorph is also documented. Monophyly ofP. islandicas. lat. (i.e. includingP. sp. AsensuO’Brienet al., from Canada) is significantly supported based on ITS sequences and corroborated by molecular synapomorphy (absence of the ITS1 hypervariable region). Analysis of therbcLX locus indicates the cyanobiont ofP. islandica(Nostocsp.) comprises strains belonging to a pool of Icelandic genotypes, some of which are present in otherPeltigeraspecies, includingP.“neorufescens”, another taxon new to Iceland collected during this study. Association with photobionts that are shared by other local species suggestsP. islandicamay be well established in Iceland, but a review of herbarium collections as well as broader field surveys are needed to better characterize its geographical distribution.

Spilonema was originally described to accommodate an unusual group of cyanolichens with thread-like, cushion-forming thalli, and has long been placed in Coccocarpiaceae based on ascomatal development. However, Spilonema is the only genus of Peltigerales to include species lichenized with the cyanobacterial genus Stigonema, and the evolutionary relationships of Spilonema to other genera in the family have yet to be tested using molecular data. We present evidence from combined nuclear 28S, 18S and mitochondrial 12S rDNA to confirm the placement of the core species of Spilonema (S. paradoxum and S. revertens) in Coccocarpiaceae. Our data further show that despite possessing a different genus of photobiont (Scytonema), the north Pacific endemic genus Spilonemella must be included within Spilonema, suggesting that closely related species of the genus have changed photobionts in the course of evolution. However, we recovered Spilonema dendroides, one of the only lichens known to associate with the cyanobacterial genus Hyphomorpha, as only distantly related to the Coccocarpiaceae. The evolutionary relationships of this species are as yet unclear but it may occupy a basal position in the Peltigerales. We create for this species the new genus Erinacellus T. Sprib., Muggia & Tønsberg.

Nephroma occultum is a COSEWIC listed cyanolichen of “Special Concern”. It is endemic to old-growth cedar-hemlock forests in western North America. This is the first study to place N. occultum into a phylogenetic framework using nucleotide sequence and secondary structure data. It also addresses the phylogenetic relationship between N. occultum and N. arcticum. Analysis of fungal Internal Transcribed Spacer (ITS) ribosomal DNA (rDNA) produced four major clades. The cyanobacterial transfer RNALeu intron (tRNALeu) from N. occultum was separated from that of N. isidiosum and fell between the Eurasian and North American epiphytic taxa. Examination of length and complexity of the folded secondary structures revealed different trends in the ITS1 and ITS2 rRNA regions. Even though N. occultum is endemic to North America, it seems more closely related to South American temperate rainforest species than to the sympatric N. arcticum. Nephroma occultum is alone among the studied species of Peltigerales in having an exceptionally long ITS1 region, and a different tRNALeu intron DNA sequence of the photobiont suggesting association with a unique genotype of Nostoc. It may be argued that the fitness of N. occultum may be influenced by the complex ITS1 RNA structure, a unique photobiont genotype undergoing a genetic bottleneck, no sexual reproduction to generate variation, and the inability to associate with different photobionts to adapt to changing habitats.

The assertion that the blue-greens (‘cyanobacteria’) are bacteria and not algae has led to alternative concepts for both of the latter terms. Bacteria is now often used to designate the prokaryote kingdom, that includes the blue-greens, while in other contexts it means specifically those prokaryotes that are not blue-greens. The term algae, on the other hand, has no biosystematic implications; it encompasses many phylogenetically independent lineages characterized by oxygen-evolving photosynthesis. The algal status of the blue-greens is therefore not compromised by their classification among the bacteria. Current lichenological terminology, however, reflects the view that the blue-greens are not algae, thereby diverging from the concept of algae employed in phycology. The purpose and utility of terms that group organisms according to structural, functional and ecological criteria are insufficiently appreciated. These concepts do not compete with phylogenetic/biosystematic classifications, but rather complement them.

Canopy lichen abundance was assessed by size class on regenerating hemlocks, comparing trees of similar size and age (c. 120–140 yrs) growing in the understorey of old-growth cedar-hemlock stands with those growing in adjacent even-aged hemlock stands (natural origin patches c. 1–3 ha in size). Five chlorolichen taxa were associated with old-growth understorey trees: Cavernularia hultenii, Hypogymnia vitatta, Parmelia hygrophila, Platismatia norvegica, and Usnea spp. Lobaria pulmonaria was the most abundant cyanolichen on regenerating hemlock in the old-growth forest stands, particularly in lower canopy (under 12 m) exposures. However, other cyanolichen taxa such as Nephroma helveticum, Sticta fulginosa, and Pseudocyphellaria anomala, reached their greatest abundance at mid-canopy (12–24 m) positions. Smaller cyanolichen thalli (2) were abundant on regenerating hemlocks across all canopy positions in the old-growth forest, raising the question as to whether or not cyanolichen thalli in mid- to upper-canopy environments represented long-established individuals facing severe growth constraints, or were simply thalli that had experienced higher rates of fragmentation, and thus did not achieve larger sizes. In comparison, cyanolichens of all taxa were essentially absent from the small-patch even-aged forest stands. Given that dispersal of propagules was not likely a major limiting factor, these 120–140 year old even-age stands may not yet have attained sufficient old-growth characteristics (especially canopy microclimate and canopy throughflow enrichment) to support cyanolichen growth. These findings have major conservation biology implications for wet interior cedar-hemlock forests in British Columbia, where forest harvesting is creating a mosaic of even-aged stands, whose projected age at the time of next harvest (rotation age) will be 120 years or less.

Arctomia teretiuscula sp. nov. (Arctomiaceae) is described from Sichuan Province, China. A minutely coralloid, bryophilous cyanolichen, it is a further example of the biogeographical link between the lichen biotas of the Himalayan region and the Arctic. A key to the three accepted species of Arctomia is provided.

Cyanopyrenia japonica Harada, gen. et sp. nov. is described. It is characterized by having a coccoid cyanobiont, perithecia, sparsely branched paraphyses, thin-walled bitunicate asci, and simple hyaline spores. It resembles Verrucaria, Pyrenocollema, and some Lichinaceae in certain morphological respects, but has no clear affinities. It is known only from the type locality in Shikoku, southwestern Japan, where it grows on frequently submerged rocks in the main flow of a river.