Manuela Dal-Forno

A single macrolichen constitutes hundreds of unrecognized species

Significance Macrolichens are considered to be well known, including the tropical montane basidiolichen fungus Dictyonema glabratum, also known as Cora pavonia, an important component of threatened paramo ecosystems, where it acts as a biological fertilizer due to its ability to fix atmospheric nitrogen. This lichen was long believed to represent a single species, but after revising this number to 16 in two genera (Cora and Corella), here we show that at least 126 phylogenetically and morphologically distinct species are contained within this group, with statistical analysis predicting more than 400. Our findings underline the importance of accurately documenting species richness for conservation purposes and support the notion of neotropical paramos as hotspots of recent diversification in plants, animals, and fungi. The number of Fungi is estimated at between 1.5 and 3 million. Lichenized species are thought to make up a comparatively small portion of this figure, with unrecognized species richness hidden among little-studied, tropical microlichens. Recent findings, however, suggest that some macrolichens contain a large number of unrecognized taxa, increasing known species richness by an order of magnitude or more. Here we report the existence of at least 126 species in what until recently was believed to be a single taxon: the basidiolichen fungus Dictyonema glabratum, also known as Cora pavonia. Notably, these species are not cryptic but morphologically distinct. A predictive model suggests an even larger number, with more than 400 species. These results call into question species concepts in presumably well-known macrolichens and demonstrate the need for accurately documenting such species richness, given the importance of these lichens in endangered ecosystems such as paramos and the alarming potential for species losses throughout the tropics.

Starting from scratch: Evolution of the lichen thallus in the basidiolichen Dictyonema (Agaricales: Hygrophoraceae).

Phylogenetic studies indicate that the basidiolichen genus Dictyonema s.lat., often thought to represent only a single genus with few species, includes several well-supported genus-level clades, all of which form associations with a unique lineage of obligately lichenized cyanobacteria (Rhizonema). In an attempt to elucidate the evolution and genus- and species-level diversification in Dictyonema s.lat., we generated 68 new sequences of the nuclear large subunit rDNA (nuLSU), the internal transcribed spacer (ITS), and the RNA polymerase II subunit (RPB2), for 29 species-level lineages representing all major clades of Dictyonema s.lat. and most of the species currently known. The multilocus phylogeny obtained via maximum likelihood and Bayesian approaches indicates the presence of five genus-level groups: a basal clade, Cyphellostereum, that is sister to the rest of the species, a paraphyletic grade representing Dictyonema s.str., and three clades representing the genera Acantholichen, Cora, and Corella. To determine the evolutionary transformations of the lichenized thallus in the group, ancestral character state reconstruction was done using six characters (lichenisation, thallus type, cortex type, hyphal sheath and haustorial type, photobiont morphology, and basidiocarp type). Our analysis indicates a progressive development of the lichenized thallus from loosely organized filamentous crusts with separate, cyphelloid basidiocarps in Cyphellostereum, to filamentous crusts with derived hyphal sheath and cyphelloid-stereoid basidiocarps partially incorporated into the lichen thallus in Dictyonema, to squamulose-foliose thalli with corticioid basidiocarps entirely supported by the lichen thallus in Cora. These results indicate a remarkable evolutionary integration of lichenized and reproductive tissues in Dictyonema s.lat., supporting the hypothesis that, at least in this case, lichenized thalli may have evolved from reproductive structures in their nonlichenized ancestors.

A first assessment of Galapagos basidiolichens

As part of an ongoing comprehensive inventory of Galapagos lichens, a first assessment of the morphology and anatomy of basidiolichens from the archipelago is presented here. It is the basis for further studies of the taxonomy, ecology and biogeography of this poorly known group of lichens. Four genera, all in Hygrophoraceae, can be distinguished: Acantholichen, Cora, Cyphellostereum and Dictyonema. Both Acantholichen and Cora are characterized by chroococcoid cyanobionts and a heteromerous thallus with a distinct upper cortex and photobiont layer. The monotypic Acantholichen pannarioides is entirely composed of small, branched, inflated squamules that appear densely pruinose because their cortical hyphae bear characteristically swollen, densely spinose end cells (acanthohyphidia); this species has never been observed fertile. The common Cora glabrata is foliose, forming large, radially zonate, conch-like, often tiled thalli, when fertile with circular lines of basidiocarps on its lower side. Dictyonema is distinguished by filamentous cyanobionts and distinctly filamentous thalli that are homomereous (i.e., not distinctly layered); all species of Dictyonema s.str. have trichomes (filamentose cyanobacterial photobionts) closely enveloped by fungal cells of a jigsaw pattern. In D. sericeum thallus filaments (i.e., individual fibrils) aggregate to form shelf-like structures similar in appearance to polyporoid bracket fungi; basidiocarps develop in irregular patches on the lower side of these shelves. In contrast, fibrils of D. schenkianum grow encrusting their substrate with irregularly to suberect trichomes, occasionally bearing basidiocarps dispersed across the thallus. Two other species in Galapagos show adpressed growth form and are described here as new: Dictyonema pectinatum, which is characterized by large parallel fibrils with paler, papillate tips, and D. galapagoense, characterized by thin trichomes of more squarrish elongate cells. The genus Cyphellostereum is represented by two species: the newly described C. imperfectum and an unnamed Cyphellostereum sp., both phenotypically similar to free-living cyanobacterial filaments. Cyphellostereum imperfectum has narrow photobiont filaments with irregular hyphal sheath leaving interspaces; macroscopically it shows a bluish green thallus with a distinct prothallus. Cyphellostereum sp. has a rather uncommon basidiolichen appearance: thin sctytonematoid fibrils surrounded by straight fungal cells forming shiny tufts. The new combination Cyphellostereum nitidum is also proposed. The ecology and taxonomy of Galapagos basidiolichens is briefly discussed and a key and short descriptions of all species are presented.

From one to six: unrecognized species diversity in the genus Acantholichen (lichenized Basidiomycota: Hygrophoraceae)

We present a taxonomic revision of the lichenized basidiomycete genus Acantholichen, species of which produce a characteristic blue-gray, microsquamulose thallus with spiny apical hyphal cells known as acanthohyphidia. Since its discovery, the genus was thought to be monospecific, only including the generic type, A. pannarioides. However, a detailed morphological and anatomical study of recently collected specimens from the Galápagos, Costa Rica, Brazil and Colombia, combined with a molecular phylogenetic analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and 28S of the nuc rDNA and RPB2 sequences, revealed a much more diverse and widespread species assemblage. Based on the results of these analyses, we describe five new species in the genus: A. albomarginatus, A. campestris, A. galapagoensis, A. sorediatus and A. variabilis. We also provide an identification key to all species, anatomical and morphological descriptions, photographs and a table comparing main characters of each species.

Dictyonema huaorani (Agaricales: Hygrophoraceae), a new lichenized basidiomycete from Amazonian Ecuador with presumed hallucinogenic properties

Abstract Dictyonema huaorani, a new species represented by a well-developed specimen found in the Ecuadorian Amazon region, is described in this paper. The material was collected during a Harvard ethnobotanical expedition in 1981 and originally determined by Mason E. Hale Jr. as belonging in the genus Dictyonema (D. sericeum s.lat.) and possibly representing an undescribed species. The species is morphologically distinctive in forming densely woven, semicircular thalli, closely resembling those of the paleotropical D. ligulatum but lacking clamps and with hyphal sheath around the photobiont filaments that resembles those of Cyphellostereum species. The species was reported to have hallucinogenic properties and chemical analyses suggest certain substances present that are shared with the hallucinogenic mushroom Psilocybe cubensis. Due to our inability to use pure reference compounds and scarce amount of sample for compound identification, however, our analyses were not able to determine conclusively the presence of hallucinogenic substances.

Four new species of Graphis ( Ostropales: Graphidaceae ) from Brazil

Four species of the genusGraphisAdans. are described as new to science, namelyG. archeri, G. invisibilis, G. lueckingii and G. paranaensis. These new species were found growing in restinga forest in southern Brazil.

Molecular data support establishment of a new genus for the lichenicolous species Neobarya usneae (Hypocreales)

Abstract Neobarya usneae Etayo is a relatively uncommon lichenicolous fungus that forms distinctive obpyriform ascomata on species of Usnea. The species is one of five known lichenicolous species in Neobarya, a genus established in the Clavicipitaceae that contains a variety of mycoparasitic species. The only molecular data for Neobarya species available in GenBank are for unidentified Neobarya species. We obtained sequences of ITS and nrLSU representing a culture and herbarium specimens of N. usneae from New Brunswick, Canada, and from a herbarium specimen of N. parasitica (Fuckel) Lowen, the type species of the genus, collected in Luxembourg, to determine the phylogenetic placement of these species. Our results indicate that N. usneae is not closely related to the type of Neobarya in the Clavicipitaceae, but is instead a member of the Hypocreaceae, the first lichenicolous species known for certain from this Hypocrealean family. Based on these results, we are now establishing a new genus, Lichenobarya, for N. usneae in the Hypocreaceae, and encouraging further study of other Neobarya species to establish their phylogenetic relationships, given the potential for genetic heterogeneity in the group.