Paul M. Kirika

Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi.

We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.

The monotypic genus Bulborrhizina belongs to Bulbothrix sensu lato (Parmeliaceae, Ascomycota)

Abstract The phylogenetic position of the monotypic genus Bulborrhizina is studied using molecular data from three loci (mtSSU, nuLSU and ITS) aligned with sequences from 95 other samples of parmelioid lichens. Bulborrhizina africana clusters within the predominantly paleotropical Bulbothrix ‘clade II’ with strong support. However, its relationships within this clade remain uncertain. The morphological characters used to circumscribe Bulborrhizina are interpreted as adaptations to the habitat of this species in semi-arid regions of eastern Africa. A formal synonymy of the genus Bulborrhizina with either Bulbothrix or Parmelinella is postponed until sequences of the type species of Bulbothrix become available that will allow us to identify which of the two clades of species currently placed in Bulbothrix represents Bulbothrix s.str.

Molecular data show that Hypotrachyna sorocheila (Parmeliaceae) is not monophyletic

Abstract Lichens that reproduce by means of vegetative propagules (soredia or isidia) are generally thought to have broad geographic distributions. However, recent studies have shown that some asexually reproducing lichens with broad distribution may be comprised of multiple, independent species-level lineages. Our understanding of species diversity in asexually reproducing lichenized fungal species may be further confounded by the fact that otherwise morphologically similar taxa separated based on the presence or absence of vegetative reproductive structures may in fact be conspecific. In this study, we investigate genetic diversity of the pantropical sorediate species Hypotrachyna sorocheila using molecular sequence data. Specifically, we generated a three-marker dataset for Hypotrachyna subgen. Everniastrum specimens, and reconstructed a multilocus, molecular phylogeny. Our results show that sorediate samples phenotypically identifiable as H. sorocheila do not form a monophyletic group, but form two distinct species-level lineages. Although our data support the pantropical distribution of H. sorocheila s.str., including populations in East Africa, a distinct species-level clade was found in Asia and is described as a new species here, H. himalayana Divakar & Kirika sp. nov. This study highlights the fact that the taxonomic significance of reproductive traits may vary among lineages of lichen-forming fungi, and that there is need for careful case-by-case studies.

New Records of Lichen-Forming Fungi from Kenya

ABSTRACT Diversity of tropical lichen-forming fungi, especially crustose lichens is currently poorly known. Since lichens are important bioindicators of air pollution, forest health, and climate change, we addressed the lichen diversity in Kenya. Our study focused on the diversity of lichen-forming fungi in the Mount Kenya montane forests, where we sampled corticolous lichens at ten localities in the Mount Kenya forest. The lichen diversity in the study area was very rich with fifty-nine species recorded for the first time from Kenya; 18 of them are new records for the African continent. Diagnostic features and distribution areas are given for each species reported. The crustose genera Auriculora, Candelariella, Clandestinotrema, Diorygma, Hemithecium, Lecanactis, Lepraria, Letrouitia, Megalospora, Mycoporum, Ocellularia, Placynthiella, Piccolia, Ramboldia, Tephromela and Thelotrema are reported here from Kenya for the first time. The majority of new records belong to pan- or palaeotropical species, in addition to cosmopolitan elements.

Circumscription of the genus Lepra, a recently resurrected genus to accommodate the "Variolaria"-group of Pertusaria sensu lato (Pertusariales, Ascomycota)

Pertusarialean lichens include more than 300 species belonging to several independent phylogenetic lineages. Only some of these phylogenetic clades have been comprehensively sampled for molecular data, and formally described as genera. Here we present a taxonomic treatment of a group of pertusarialean lichens formerly known as “Pertusaria amara-group”, “Monomurata-group”, or “Variolaria-group”, which includes widespread and well-known taxa such as P. amara, P. albescens, or P. ophthalmiza. We generated a 6-locus data set with 79 OTUs representing 75 species. The distinction of the Variolaria clade is supported and consequently, the resurrection of the genus Lepra is followed. Thirty-five new combinations into Lepra are proposed and the new species Lepra austropacifica is described from mangroves in the South Pacific. Lepra is circumscribed to include species with disciform ascomata, a weakly to non-amyloid hymenial gel, strongly amyloid asci without clear apical amyloid structures, containing 1 or 2, single-layered, thin-walled ascospores. Chlorinated xanthones are not present, but thamnolic and picrolichenic acids occur frequently, as well as orcinol depsides. Seventy-one species are accepted in the genus. Although the distinction of the genus from Pertusaria is strongly supported, the relationships of Lepra remain unresolved and the genus is tentatively placed in Pertusariales incertae sedis.