Tor Tønsberg

Phylogeography of Cavernularia hultenii: evidence of slow genetic drift in a widely disjunct lichen

Population structure and history is poorly known in most lichenized ascomycetes. Many species display large‐scale infraspecific disjunctions, which have been explained alternately by range fragmentation in species of high age and widespread long‐distance dispersal. Using the lichen Cavernularia hultenii, which is widely disjunct across North America and Europe, Pleistocene and Holocene population history was inferred. The internal transcribed spacer (ITS) and part of the the intergenic spacer (IGS) region of the nuclear ribosomal DNA were sequenced in 300 individuals representing 62 populations across the range of the species. While four ancestral haplotypes are found in all areas, none of the observed tip haplotypes is present in more than one of the three part ranges. Although this is evidence for a past fragmentation event, nested clade analysis (NCA) remains equivocal in the choice between allopatric fragmentation and long‐distance dispersal. Mismatch distributions indicate exponential population growth, probably during postglacial invasion of C. hultenii into formerly glaciated areas of western North America. The presence of one southern and at least one northern glacial refugium in South Central Alaska is inferred. Evidence for another refugium in the Queen Charlotte Islands or Alexander Archipelago is inconclusive because of sparse sampling. However, a range expansion was not confirmed unambiguously by NCA. The limited power of NCA to infer past range fragmentations and expansions is due apparently to the shallow haplotype network and widespread ancestral haplotypes. This can be explained by slow genetic drift causing incomplete removal of ancestral haplotypes from the postfragmentation and postexpansion areas.

Most species of Lepraria and Leproloma form a monophyletic group closely related to Stereocaulon

The phylogenetic position of members of the entirely asexually reproducing lichen-forming genera Lepraria and Leproloma was investigated using sequence data from the ITS1-5.8S-ITS2 and small subunit (SSU) nuclear ribosomal DNA. Phylogenetic reconstructions were carried out using a likelihood-based Bayesian Markov chain Monte Carlo (MCMC) tree sampling technique and the unweighted least squares optimality criterion, the latter based on maximum likelihood distances obtained via an alignment-free distance estimation technique. The results indicate that most species currently referred to Lepraria and Leproloma form a single monophyletic group. This monophyletic group is the sister group to Stereocaulon and Muhria and belongs in the Stereocaulaceae (Lecanorales, Lecanoromycetes, Ascomycota ). This indicates that an ancestor of Lepraria switched from a sexual to an asexual mode of dispersal. Subsequent speciation must have taken place in the absence of sexual processes, which contradicts the view of asexual taxa as ‘evolutionary dead ends’. Leproloma is polyphyletic and nested within Lepraria. Lepraria flavescens is a Lecanora probably belonging in subgenus Glaucomaria. Lepraria lesdainii and L. obtusatica are unrelated to each other and to other species currently referred to Lepraria or Leproloma. Leprocaulon and Crocynia are distantly related to the core group of Lepraria and Leproloma.

Lichens and lichenicolous fungi of the Klondike Gold Rush National Historic Park, Alaska, in a global biodiversity context

Abstract The lichen flora of southeast Alaska has been explored for over 100 years, but remains poorly known. In the first survey of its kind from the region, we report 766 taxa of lichens and lichenicolous fungi from the Klondike Gold Rush National Historic Park. Coming from a park only 53 km2 in size, this represents one of the largest numbers of lichenized and lichenicolous fungi per unit area ever reported and the largest number ever reported from any United States National Park of any size. One lichen genus, four lichen species and one species of lichenicolous fungus are described as new to science: Steineropsis alaskana gen. et sp. nov. (Peltigerales), Coccotrema hahriae and Pertusaria mccroryae (both Pertusariales), Stereocaulon klondikense (Lecanorales) and Corticifraga scrobiculatae (Lecanoromycetes incertae sedis). The new combinations Coccotrema minutum and Nesolechia fusca are made and Parmelia elongata is reduced to synonymy under Hypogymnia duplicata. Seventy-five taxa could not be assigned a species name at this time and represent a pool of critical and/or potentially undescribed taxa. Thirty-four taxa are new or confirmed for North America, including seventeen lichen taxa, one species of saprophytic Dothideomycetes, and sixteen species of lichenicolous fungi. Five taxa of eastern North American distribution are reported for the west for the first time. A total of 196 taxa are new for Alaska. We report the presence of novel secondary chemical compounds in Bryoria, Cladonia, Hypogymnia and Pertusaria. Based on a Chao analysis of single and two-time occurrences we estimate we have captured not more than 83% of the macrolichen and 64% of the microlichen flora, with the total flora likely exceeding 1000 taxa. We provide an overview of the lichen inventories with highest species number worldwide and discuss the Klondike in the context of broader patterns in lichen richness. Global models of climate change in the coming century are unanimous in predicting greater temperature increases at higher latitudes than at low latitudes. We hope that our data will lead to a reconsideration of the potential extent of biodiversity at high latitudes.

Additions to the Lichen Flora of North America XI

Abstract Biatora printzenii sp. nov. is described from eastern North America. Cheiromycina flabelliformis, Chrysothrix chrysophthalma, Opegrapha corticola, and Rinodina flavosoralifera are reported new to North America. The report in The Bryologist 99: 196 (1996) of Fuscidea lightfootii as new to North America was based on misidentifications.

Contributions to an epiphytic lichen flora of northwest North America: I. Eight new species from British Columbia inland rain forests

Abstract Recent surveys of the inland rain forests of British Columbia and adjacent regions have brought to light an unexpectedly rich epiphytic lichen flora, including several species apparently new to science. In the first of a series of papers, we describe eight species discovered during these surveys as new: Absconditella amabilis T. Sprib. (Ostropales), Bacidina contecta S. Ekman & T. Sprib., Biatora aureolepra T. Sprib. & Tønsberg, Biatora ligni-mollis T. Sprib. & Printzen (all Lecanorales), Collema coniophilum Goward (Peltigerales), Pertusaria diluta C. Björk, G. Thor & T. Wheeler (Pertusariales), Schaereria brunnea C. Björk, T. Sprib. & T. Wheeler (Ostropomycetidae incertae sedis) and Scoliciosporum abietinum T. Sprib. (Lecanorales). We also call attention to a ninth species, Bacidina sp. A, a poorly known and possibly undescribed colonizer of moribund cyanolichens. A majority of the above species appear to be confined to old-growth forests, while two (Biatora ligni-mollis and Schaereria brunnea) are currently known only from “antique” forests older than about 500 years. Many additional undescribed epiphytic lichens are known from inland rain forests, underscoring the need for further baseline biodiversity research in light of its ongoing disappearance as a result of resource extraction. In addition to the eight new species, we report Absconditella celata as new to North America, Absconditella lignicola as new to Canada and Montana, Bacidina chloroticula as new to British Columbia and Gyalideopsis piceicola as new to Montana.

Sticta oroborealis sp. nov., and Other Pacific North American Lichens Forming Dendriscocauloid Cyanotypes

Abstract Three lichen species forming both a foliose chlorotype and a dendriscocauloid cyanotype are documented from western North America. Lobaria amplissima is reported from northern California and southeastern Alaska and is new to North America. Sticta oroborealis Goward & Tønsberg, sp. nov. is described from a small area in north coastal British Columbia. The cyanotype of Sticta wrightii, hitherto unknown, is reported from coastal southeastern Alaska. The cyanotypes of all these species occur primarily as epiphytes in old-growth forests supporting a high cyanolichen diversity. The occurrence of “Dendriscocaulon” intricatulum (Nyl.) Henssen in Pacific North America is questioned.

Convergent evolution of a symbiotic duet: The case of the lichen genus Polychidium (Peltigerales, Ascomycota)

PREMISE OF THE STUDY Thallus architecture has long been a powerful guide for classifying lichens and has often trumped photobiont association and ascomatal type, but the reliability of these characters to predict phylogenetic affinity has seldom been tested. The cyanolichen genus Polychidium unites species that have strikingly similar gross morphology but consort with different photobiont genera. If Polychidium were found to be monophyletic, photobiont switching among closely related species would be suggested. If, however, species were found to arise in different lineages, a convergent body plan and ascomatal type evolution would be inferred. METHODS We tested the monophyly of Polychidium with a multilocus phylogeny based on nuclear and mitochondrial sequence data from all known Peltigeralean families and reconstructed ancestral states for specific thallus architecture and ascomatal ontogeny types relative to Polychidium and other clades. KEY RESULTS We found that Polychidium consists of two species groups that arose independently in different suborders within the Peltigerales, associated with Nostoc and Scytonema photobionts, respectively. We infer from ancestral character state reconstruction that dendroid thallus architecture evolved independently in these two lineages. CONCLUSIONS The independent development of similar dendroid thallus architecture in different fungal suborders with different photobionts represents a clear and previously overlooked example of convergent evolution in lichens. Our results also suggest a pattern of character state conservation, loss, and reversion in ascomatal ontogeny types, hitherto considered conserved traits useful for higher level ascomycete systematics.

(−)-Allo-pertusaric acid and (−)-dihydropertusaric acid from the lichen Pertusaria albescens☆☆☆

Abstract The structures of two γ-lactone carboxylic acids from the lichen Pertusaria albescens , (−)-allo-pertusaric acid and (−)dihydropertusaric acid, have been elucidated by spectroscopic and chemical methods. From P. ophthalmiza , taraxerone and a mixture of long chain aliphatic alcohols and fatty acids have been isolated.

A New Species of Megalaria from the North American West Coast, and Notes on the Generic Circumscription

Megalaria brodoana S. Ekman & Tensberg sp. nov. (Lecanorales, lichenized Asco- mycotina) is described from western North America (British Columbia, Washington, and Oregon). It is recognized by the following characteristics: a more or less granular, often bluish thallus; dark purplish brown to black, thick-margined apothecia; a greenish (K+ pure green, N+ purple-red) pigment in the epithecium; a brown-red to brown-purple (K+ red to purple-red, N+ orange-red) pigment in the proper exciple, hypothecium, and lower part of hymenium; a pure brown (K-, N-) pigment in the hypothecium; and one-septate, thick-walled, widely ellipsoid to subglobose spores. Megalaria brodoana occurs in humid, coastal forests along with a high number of oceanic lichens. The main phorophyte is Alnus rubra. The circumscription of the genus Megalaria is discussed. The combinations Megalaria columbiana (G. Merr.) S. Ekman and M. albocincta (Degel.) Tensberg are made.

Lecanora thysanophora, a Common Leprose Lichen in Eastern North America

Abstract Lecanora thysanophora R. C. Harris, n. sp. is described. It is a common lichen in eastern North America, most often found as a sterile corticolous crust, but apothecia are not uncommon when the species grows along streams. Besides being recognizable in the field, it is distinctive chemically, containing usnic acid, zeorin, often porphyrilic acid, and several species-specific terpenoids.