Eimy Rivas Plata

Fungi evolved right on track.

Dating of fungal divergences with molecular clocks thus far has yielded highly inconsistent results. The origin of fungi was estimated at between 660 million and up to 2.15 billion y ago, and the divergence of the two major lineages of higher fungi, Ascomycota and Basidiomycota, at between 390 million y and up to 1.5 billion y ago. Assuming that these inconsistencies stem from various causes, we reassessed the systematic placement of the most important fungal fossil, Paleopyrenomycites, and recalibrated internally unconstrained, published molecular clock trees by applying uniform calibration points. As a result the origin of fungi was re-estimated at between 760 million and 1.06 billion y ago and the origin of the Ascomycota at 500–650 million y ago. These dates are much more consistent than previous estimates, even if based on the same phylogenies and molecular clock trees, and they are also much better in line with the fossil record of fungi and plants and the ecological interdependence between filamentous fungi and land plants. Our results do not provide evidence to suggest the existence of ancient protolichens as an alternative to explain the ecology of early terrestrial fungi in the absence of land plants.

A new classification for the family Graphidaceae (Ascomycota: Lecanoromycetes: Ostropales)

A revised classification for the emended family Graphidaceae is proposed, based on recent phylogenetic studies, including the finding that three previously separated families (Asterothyriaceae, Gomphillaceae, Thelotremataceae) are nested within Graphidaceae and in part polyphyletic. The family comprises three major clades which are here delimited as subfamilies Fissurinoideae, Gomphilloideae, and Graphidoideae. The latter is composed of three major clades which are formally delimited as tribes Graphideae, Ocellularieae, and Thelotremateae. In addition, three new genera are described to accommodate the Ocellularia clandestina (Clandestinotrema) group, the Ocellularia cruentata group (Cruentotrema) and Myriotrema pycnoporellum (Pycnotrema). Keys are provided for the species placed in the new genera.

When family matters: an analysis of Thelotremataceae (Lichenized Ascomycota: Ostropales) as bioindicators of ecological continuity in tropical forests

We analysed patterns of habitat and microhabitat preferences of 19 families (comprising 135 genera and 950 species) of crustose, corticolous lichens in Costa Rica (Arthoniaceae, Arthopyreniaceae, Coenogoniaceae, Graphidaceae, Lecanoraceae, Letrouitiaceae, Monoblastiaceae, Pertusariaceae, Physciaceae, Pilocarpaceae, Porinaceae, Pyrenulaceae, Ramalinaceae, Roccellaceae, Strigulaceae, Teloschistaceae, Thelenellaceae, Thelotremataceae, Trypetheliaceae), in order to test whether Thelotremataceae are suitable predictors of undisturbed tropical rain forest and can be used as bioindicators of ecological continuity. The dataset consisted of 12,215 specimen samples and six environmental parameters recorded for each sample (altitude, degree of seasonality, vegetation type, disturbance level, substrate nature, light exposure), which were analysed by a multivariate approach using principal component analysis (PCA). The analysis showed that three of the 19 families, Letrouitiaceae, Porinaceae, and Thelotremataceae, showed significant preferences for undisturbed primary to old growth secondary forest, fully shaded to semi-exposed microhabitats, and the bark of mature tree trunks, parameters assumed to be correlated with ecological continuity of closed rain forest habitats. Thelotremataceae had broader altitudinal range than Letrouitiaceae and Porinaceae and significantly higher genus and species diversity (16 genera, 130 species) compared to Porinaceae (4 genera, 40 species) and Letrouitiaceae (1 genus, 5 species). Our results support the hypothesis that Thelotremataceae perform best as predictors of undisturbed dry and lowland to montane rain forest and are the most suitable lichen bioindicators of ecological continuity in these ecosystems. In contrast, Lecanoraceae, Pertusariaceae, Physciaceae, and Teloschistaceae, were found to be predictors of disturbed and pioneer (micro-)habitats. We also found that, among a variety of parameters tested, the Index of Ecological Continuity (IEC), adapted to the use of Thelotremataceae in tropical forests, performs best in terms of predicting disturbance levels and site history. A semi-taxonomic approach identifying morphotypes rather than genera or species yielded the same results, making this method suitable for a broader spectrum of potential users.

A world-wide key to the thelotremoid Graphidaceae , excluding the Ocellularia - Myriotrema - Stegobolus clade

In the course of an ongoing systematic and taxonomic revision of the lichen family Graphidaceae (including Thelotremataceae ), we present world-wide keys to the currently accepted thelotremoid genera and species, excluding the columellate taxa and their relatives of the Ocellularia - Myriotrema - Stegobolus clade ( Melanotrema , Myriotrema , Ocellularia , Ocellularia clandestina group, Redingeria , Stegobolus ), which will be treated in a forthcoming paper. The keys include all genera and species with chroodiscoid, lepadinoid, and topeliopsidoid apothecia and other taxa featuring periphysoids or fibrils, and their relatives. Taxa keyed out to genus and species level are Acanthotrema , Chapsa , Chroodiscus , Diploschistes , Fibrillithecis , Gyrotrema , Leptotrema , Leucodecton , Melanotopelia , the ‘ Ocellularia ’ cruentata group, Pseudoramonia , Reimnitzia , Schizotrema , Thelotrema , Topeliopsis and Wirthiotrema . Over 260 species are treated, including a few yet unnamed taxa. The following taxonomic and nomenclatural novelties are introduced: Acanthotrema frischii Lucking sp. nov., Chapsa aggregata (Hale) Sipman & Lucking comb. nov., C. albida (Nyl.) Lucking & Sipman comb. nov.; C. albomaculata (Sipman) Sipman & Lucking comb. nov., C. boninensis (Tat. Matsumoto) Rivas Plata & Mangold comb. nov., C. elabens (Mull. Arg.) Rivas Plata & Mangold comb. nov., C. imperfecta (Hale) Rivas Plata & Lucking comb. nov., C. laceratula (Mull. Arg.) Rivas Plata & Lucking comb. nov., C. magnifica (Berk. & Broome) Rivas Plata & Lucking comb. nov., C. meghalayensis (Patw. & Nagarkar) Lumbsch & Divakar comb. nov., C. meridensis (Kalb & Frisch) Lucking, Lumbsch & Rivas Plata comb. nov., C. mirabilis (Zahlbr.) Lucking comb. nov., C. neei (Hale) Mangold & Lucking comb. nov., C. paralbida (Riddle) Rivas Plata & Lucking comb. nov., C. pseudoexanthismocarpa (Patw. & C. R. Kulk.) Rivas Plata & Lucking comb. nov., C. pulvereodisca (Hale) Rivas Plata & Mangold comb. nov., C. scabiomarginata (Hale) Rivas Plata & Lucking comb. nov., C. waasii (Hale) Sipman & Lucking comb. nov., Fibrillithecis argentea (Mull. Arg.) Rivas Plata & Lucking comb. nov., F. carneodisca (Hale) Rivas Plata & Lucking comb. nov., F. confusa Lucking, Kalb & Rivas Plata spec. nov., F. diminita (Hale) Rivas Plata & Lucking comb. nov., F. eximia (R. C. Harris) Rivas Plata & Lucking comb. nov., F. fissurata (Nagarkar & Hale) Rivas Plata & Lucking comb. nov., F. gibbosa (H. Magn.) Rivas Plata & Lucking comb. nov., Leucodecton desquamescens (Vain.) Lucking comb. nov., L. oxysporum (Redinger) Lucking comb. nov., Schizotrema cryptotrema (Nyl.) Rivas Plata & Mangold comb. nov., Thelotrema patwardhanii (Hale) Rivas Plata & Mangold comb. nov., Topeliopsis guaiquinimae (Sipman) Rivas Plata & Mangold comb. nov., and T. tuberculifera (Vain.) Rivas Plata & Mangold comb. nov. Using the examples of Fibrillithecis halei s. lat., Leucodecton compunctellum s. lat., and Thelotrema monosporum s. lat., we show how difficult species complexes can be flexibly treated in a key, allowing for either a broad concept or the distinction of several individual taxa.

Parallel evolution and phenotypic divergence in lichenized fungi: A case study in the lichen-forming fungal family Graphidaceae (Ascomycota: Lecanoromycetes: Ostropales)

A molecular phylogeny of combined mtSSU, nuLSU, and RPB2 data revealed previously unrecognized levels of parallel evolution and phenotypic divergence in the lichen family Graphidaceae. Five clades were supported within the family: the Fissurina, Ocellularia, Graphis, Topeliopsis, and Thelotrema clades, containing 33 of the 42 currently accepted genera within the family. The results for the first time provide a fully resolved phylogeny of this family and confirm the synonymy of Graphidaceae and Thelotremataceae. Ancestral character state reconstruction using likelihood, Bayesian, and parsimony approaches indicate that lirellate ascomata evolved independently in each of the five clades. Carbonized ascomata evolved independently in at least four of the five clades. An unexpected result was the independent evolution of columella structures in the Fissurina and Ocellularia clades. Besides these more general findings, we document several cases in which evolution of several traits in parallel resulted in striking look-alikes within unrelated lineages, such as Topeliopsismuscigena and Chapsameridensis in the Topeliopsis and Thelotrema clades, Leptotremawightii, Myriotremalaeviusculum, and Leucodectonphaeosporum in the Ocellularia and Thelotrema clades, Ocellulariastylothecia and Melanotremameiosporum in the Fissurina and Ocellularia clades, and Myriotremapycnoporellum, Myriotremaclandestinum and Wirthiotremaglaucopallens in the Fissurina, Ocellularia, and Topeliopsis clades. Pagels test of independent character evolution suggested that at least for some of the traits involved in these cases, ecological constraints may have caused their evolution in parallel. The most intriguing find is the correlation between gall-forming thalli and vertical columns of calcium oxalate crystals, suggesting that these crystals do not function as light distributors, as previously assumed, but instead stabilize the thalli which are usually hollow beneath, similar to a dome-shaped structure. Ancestral character state reconstruction together with an approach to visualize the phenotype of putative ancestral lineages suggested the alpha-Graphidaceae to resemble some of the extant species currently classified in Myriotrema s.lat., with pore-like ascomata, and non-amyloid ascospores with lens-shaped lumina.

PHYLOGENETIC DIVERSITY OF TRENTEPOHLIALEAN ALGAE ASSOCIATED WITH LICHEN-FORMING FUNGI(1).

Nearly one‐fourth of the lichen‐forming fungi associate with trentepohlialean algae, yet their genetic diversity remains unknown. Recent work focusing on free‐living trentepohlialean algae has provided a phylogenetic context within which questions regarding the lichenization of these algae can be asked. Here, we concentrated our sampling on trentepohlialean algae from lichens producing a diversity of growth forms (fruticose and crustose) over a broad geographic substratum, ecological, and phylogenetic range. We have demonstrated that there is no evidence for a single clade of strictly lichenized algae; rather, a wide range demonstrated the ability to associate with lichenized fungi. Variation was also observed among trentepohlialean algae in lichens from a single geographic area and tree, suggesting that fungi in close proximity can associate with different trentepohlialean algae, consistent with the findings of trebouxiophycean algae and cyanobacteria.

Heiomasia, a new genus in the lichen-forming family Graphidaceae (Ascomycota: Lecanoromycetes: Ostropales) with disjunct distribution in Southeastern North America and Southeast Asia

Abstract Heiomasia is a new genus that includes two sterile species producing unique isidia-like structures for vegetative dispersal. Their systematic position was clarified using molecular analysis of the small subunit of the mitochondrial ribosomal DNA (mtSSU). The two species form a strongly supported clade occupying a somewhat isolated position within Graphidaceae s.lat. The new genus is based on H. sipmanii (Aptroot, Lücking & Rivas Plata) Nelsen, Lücking & Rivas Plata comb. nov., a species from Southeast Asia with disc-shaped isidia-like structures, originally described in the genus Herpothallon. The second species, H. seaveyorum Nelsen & Lücking spec. nov., is known only from Florida; it produces robust, sausage-shaped isidia-like structures.

High diversity of Graphidaceae (lichenized Ascomycota: Ostropales) in Amazonian Perú

A survey of crustose microlichens at Los Amigos Biological Station in Amazonian Peru revealed 116 species of Graphidaceae at this site. This is the second highest number of Graphidaceae ever reported for a single site world-wide, after the Surumoni crane station in Venezuela, with 131 species, and followed by Fakahatchee Strand Park Preserve in Florida, with 111 species. Based on the number of Graphidaceae found at Los Amigos, we predict the total lichen species richness at this site to be approximately 700 species. Of the 116 species encountered at Los Amigos, 59 were graphidoid species (former Graphidaceae s.str.) and 67 thelotremoid species (former Thelotremataceae). The following 18 species are described as new: Ampliotrema sorediatum Rivas Plata & Lücking, spec. nova, Chapsa hypoconstictica Rivas Plata & Lücking, spec. nova, Chapsa scabiocarpa Rivas Plata & Lücking, spec. nova, Chapsa subsorediata Rivas Plata & Lücking, spec. nova, Diorygma nigricans Rivas Plata & Lücking, spec. nova, Fissurina flavomedullosa Rivas Plata & Lücking, spec. nova, Fissurina platythecioides Rivas Plata & Lücking, spec. nova, Graphis apertoinspersa Rivas Plata & Lücking, spec. nova, Graphis pitmanii Rivas Plata & Lücking, spec. nova, Leucodecton inspersum Rivas Plata & Lücking, spec. nova, Ocellularia cicra Rivas Plata & Lücking, spec. nova, Ocellularia fenestrata Rivas Plata & Lücking, spec. nova, Ocellularia microsorediata Rivas Plata & Lücking, spec. nova, Ocellularia natashae Rivas Plata & Lücking, spec. nova, Ocellularia plicata Rivas Plata & Lücking, spec. nova, Ocellularia protoinspersa Rivas Plata & Lücking, spec. nova, Ocellularia pustulata Rivas Plata & Lücking, spec. nova, and Thelotrema amazonicum Rivas Plata & Lücking, spec. nova.

Dismantling Herpothallon: Herpothallon antillarum (Arthoniomycetes: Arthoniaceae) is a member of the genus Diorygma (Lecanoromycetes: Graphidaceae)

Abstract The new combination Diorygma antillarum (Vain.) Nelsen, Lücking & Rivas Plata is proposed. This taxon lacks ascomata and produces unique isidia-like structures for vegetative dispersal. Its systematic position was clarified by incorporating molecular sequence data from the small subunit of the mitochondrial ribosomal DNA (mtSSU) and small and large subunits of the nuclear ribososomal DNA (nuSSU and nuLSU). Our phylogenetic hypotheses suggest this taxon is not part of Herpothallon in the class Arthoniomycetes, but is supported as a member of the genus Diorygma (Graphidaceae) in the class Lecanoromycetes. This agrees with morphological and chemical features of this species.

Malmographina , a new genus for Graphina malmei (Ascomycota: Ostropales : Graphidaceae )

The new genus Malmographina Caceres, Rivas Plata & Lucking is introduced for Opegrapha plicosa Meissn. (syn. Graphis malmei Redinger), with the new combination Malmographina plicosa (Meiss.) Caceres, Rivas Plata & Lucking. The taxon is characterized by prominent, striate, orange-pigmented, non-carbonized lirellae, a more or less clear hymenium, and large, muriform, hyaline ascospores. Malmographina is most similar to Hemithecium in lirellae morphology and anatomy, but in a molecular phylogenetic analysis falls within a clade containing Phaeographis and other genera with usually inspersed hymenium and brown ascospores. Within that clade, it is thus far the only taxon that has persistently hyaline ascospores. It is otherwise similar to Pallidogramme but does not cluster within that genus. A preliminary phylogenetic analysis of the Phaeographis clade confirms monophyly of the genera Halegrapha , Pallidogramme , and Platygramme , and suggests that Phaeographis should be divided into several generic lineages and that Leiorreuma and Sarcographa perhaps be merged.