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.     

Rinodina turfaceoides,a new corticolous,blastidiate species from the Iberian Peninsula

Abstract:A new corticolous lichen, Rinodina turfaceoides, is described from the Serra de Estrela (Portugal). It is characterized mainly by the blastidiate thallus, large apothecia covered by a thick, yellow-orange pruina, large Physcia -type ascospores and chemistry. The new species is compared with the closely related but mainly muscicolous, R. turfacea, as well as with other corticolous Rinodina species with vegetative propagules, including R. colobinoides and R. disjuncta. Habit photographs of the new species and illustrations of its ascospores are also provided.     

COPPINSIA MINUTISSIMA,A NEW GENUS AND SPECIES IN THEAGYRIACEAEFROM THE BRITISH ISLES

The genusCoppinsia(lichenized Ascomycetes,Agyriaceae) with the single speciesC. minutissimasp. nov. is described as new from the British Isles. This minute lichen occurs on soil and bryophytes in metal-rich habitats. It is characterized by a minute thallus, biatorine apothecia with an almost reduced but generally cupulate exciple, slightly branched and apically unthickened paraphyses, aTrapelia-type ascus, and non-septate, ovoid ascospores.     

ASPECTS OF THE INTEGRATION OF THE TAXONOMY OF LICHENIZED AND NON-LICHENIZED PYRENOCARPOUS ASCOMYCETES

The integration of the taxonomy of lichenized and non-lichenized pyrenocarpous ascomycetes is still in progress. Within this group, at least 12 lichenization events, three re-lichenizations and at least 24 de-lichenization events, are supposed to have occurred during evolution. This is evident from the increasing amount of information regarding phylogeny and classification of pyrenocarpous fungi. The total number of lichenization events, including re- and de-lichenization, within all fungi is estimated to be at least 100. However, the vast majority of the pyrenocarpous lichens are concentrated in a few relatively large, presumably monophyletic, groups. In some cases, proposed integrations have proven to be untenable, for exampleMicrotheliopsisand with theHerpotrichiellaceae,Flavobatheliumwith theDimeriaceaeand most notably theNormandinathallus with the basidio-mycetes and its ascocarps withSphaerulinain theMycosphaerellaceae. The same is true for many cases where lichenized taxa were unwittingly included in otherwise non-lichenized groups, such asDidymosphaeriaandMassarina, or even described in new, presumably non-lichenized, genera likeHolstiella,StarbaeckiellaandTitanella.     

The occurrence of biomineralization products in four lichen species growing on sandstone in western Norway

High performance thin-layer chromatography/thin-layer chromatography, X-ray diffraction, and scanning electron microscopy analysis of thallus and lichen-rock interface samples, were undertaken to characterize biomineralization products in Fuscidea cyathoides, Ochrolechia tartarea, Ophioparma ventosa, and Pertusaria corallina, growing on sandstone in western Norway. Whewellite (monohydrate form of Ca oxalate) was found in the thallus of all species, but not in any of the weathering rinds beneath the species. A significantly higher amount of whewellite was detected in the thalli of F. cyathoides and O. ventosa than in the other two species. There were only a few differences in whewellite occurrence between the thallus edge and centre samples in the four species. HPTLC/TLC and SEM analysis indicate that lichen compounds occur within the rock beneath some of the lichen specimens. Only divaricatic acid was observed within the weathering rind beneath O. ventosa. No lichen substances were found in the weathering rind beneath F. cyathoides and P. corallina, whereas gyrophoric and lecanoric acids were found in the weathering rind beneath O. tartarea.     

Lepidostroma vilgalysii, a new basidiolichen from the New World

The lichenized basidiomycete Lepidostroma vilgalysii from Mexico is described based on morphological analyses. The species is only the second representative of the family Lepidostromataceae documented from the New World, and is one of the few described lichens with an inverted morphology, with the algae in a layer at the base of the thallus. Molecular sequence data from the nuclear ribosomal LSU locus are used to confirm the placement of the holotype in Lepidostroma and to evaluate the molecular distinctiveness of the species from all other described species in the family and genus.     

THALLUS ORGANIZATION AND DEVELOPMENT IN THE FRUTICOSE LICHENASPICILIA CALIFORNICA,WITH COMPARISONS TO OTHER TAXA

Thallus organization is examined inAspicilia californicaRosentreter, a fruticose lichen known from several localities in central and southern California. The sprawling, terete thallus branches possess a dense central medulla of thick-walled, longitudinally oriented fungal cells. This central tissue emerges at branch apices to form a darkly pigmented fungal tip. Thallus development involves the apical extension of the tip to produce a fungal tissue over which a cylindrical algal layer and cortex will eventually be formed. Apical branches are initiated by furcation entirely within the fungal tip. Lateral branches, emerging from the lichenized thallus, arise as a divergent bundle of elongate fungal cells originating in the medulla. The photobiont appears to play no direct role in initiation of apical or lateral branches. It is concluded that thallus development inA. californicaoccurs with a relatively low degree of synchrony between mycobiont and photobiont growth, similar to the pattern observed in crustose lichens with prothallic growth. A rather similar type of thallus organization is observed inA. hispida, although in that species mycobiont growth and branch initiation appear to be somewhat more closely associated with algal cell proliferation. A squamuloseAspiciliafrom central Spain produces rhizomorphs that may sometimes become invested with an algal layer and cortex, resembling the thallus axes ofA. californica.     

Notes on Neotropical Selaginella (Selaginellaceae), including new species from Panama

Three new species ofSelaginella from Panama are described and illustrated:S. correae, S. salazariae, andS. taylorii. In addition, a new name,S. smithiorum, is proposed forS. velutina A. R. Smith (nonS. velutina Cesati), and eleven new distribution records are reported. The relationships of the species are discussed and keys to some of the species are provided.     

O-Methylated mannogalactan from the microalga Coccomyxa mucigena, symbiotic partner of the lichenized fungus Peltigera aphthosa

A structural study of the carbohydrates from Coccomyxa mucigena, the symbiotic algal partner of the lichenized fungus Peltigera aphthosa, was carried out. It produced an O-methylated mannogalactan, with a (1 → 6)-linked β-galactopyranose main-chain partially substituted at O-3 by β-Galp, 3-OMe-α-Manp or α-Manp units. There were no similarities with polysaccharides previously found in the lichen thallus of P. aphthosa. Moreover, the influence of lichenization in polysaccharide production by symbiotic microalgae and the nature of the photobiont in carbohydrate production in lichen symbiosis are also discussed.     

Savoronala, a new genus of Malmideaceae (Lecanorales) from Madagascar with stipes producing sporodochia

The new genus and species Savoronala madagascariensis is a lichenized hyphomycete characterized by its pale glaucous placodioid thallus with erect, short but robust stipes apically producing sporodochia with brown, subspherical conidia, whose cells are wrapped around a single chlorococcoid algal cell. Phylogenetic analyses using nuLSU and mtSSU sequences place Savoronala in the Malmideaceae (Lecanorales). The new species was collected on Erica stems and inhabits coastal dunes near Taolanaro (southeast Madagascar). Lecidea floridensis is shown to belong to Malmidea whereas Lecidea cyrtidia and L. plebeja are also resolved in the Malmideaceae. The genus Sporodochiolichen Aptroot & Sipman is reduced into synonymy with Tylophoron.     

A NEW BYSSOID LICHEN GENUS FROM TASMANIA

The genusJarmania, based on the single speciesJ. tristis, is described. The new genus is characterized by a byssoid-leprose thallus, immarginate apothecia, asci of theBacidia-type, strongly anastomosing paraphyses and septate, acicular ascospores. The new species is corticolous and is known only from cool temperate rainforest in Tasmania. 1996 The British Lichen Society     

What is the type species of <Emphasis Type="Italic">Phanerochaete</Emphasis> (Polyporales,Basidiomycota)?

Phanerochaete velutina and the closely related species P. alnea, P. alnea subsp. lubrica, and P. rhodella are identified as distinct species based on morphological criteria and molecular analyses. Besides differences in macroscopic and microscopic basidiocarp features, the taxa differ in distribution and ITS sequence. Phanerochaete alnea is widely distributed in Eurasia and North America, whereas P. alnea subsp. lubrica is limited to the Pacific Coast of North America. Phanerochaete velutina is known from Eurasia and Alaska, and P. rhodella is found in North America only. Nomenclatural problems with the name Phanerochaete P. Karst. are discussed, and type specimens for Thelephora alnea Fr., the generic type of Phanerochaete, and Peniophora karstenii Massee are selected. Phanerochaete alnea, P. alnea subsp. lubrica, and P. velutina are described and illustrated. In addition, the synonymy of Phanerochaete robusta and P. aurantiobadia is confirmed.     

Lichenizing Rhizomorphs and Thallus Development in the Squamulose Lichen Aspicilia crespiana Rico ined. (Lecanorales,Ascomycetes)

This work describes the rhizomorphs and their relation to thallus development in the squamulose lichen Aspicilia crespiana Rico ined. The rhizomorphs capture algal cells, giving rise to new squamules terminally or laterally. The thallus thus consists of a network of lichenized squamules interlinked by mycobiontic rhizomorphs. A previously proposed comparison of lichen rhizomorphs to the prothallus (hypothallus) of crustose lichens is applied and expanded upon. Other less organized prothallic structures sometimes produced by A. crespiana are also described. The importance of lichenizing rhizomorphs as an essential feature of thallus growth in this species is emphasized and a competitive role in substrate occupation and thallus expansion is suggested.     

Research note: First report of Sporolithon ptychoides (Sporolithales,Corallinophycidae, Rhodophyta) for the Atlantic Ocean

Samples corresponding to Sporolithon ptychoides Heydrich were collected in the mesophotic zone (50 m depth) south of Espírito Santo State, Brazil. The collected material presented features characteristic of the species, namely: tetrasporangia of 75–105 × 40–55 µm grouped into sori that are raised above the surrounding vegetative thallus surface; presence of a basal layer of elongate cells in areas where the tetrasporangia develop; presence of buried tetrasporangial compartments deep in the thallus; and 3–5 cells in the tetrasporangial paraphyses. These same features said to collectively characterize S. ptychoides, were all observed in a representative specimen and the type specimen of Sporolithon dimotum (Foslie & Howe) Yamaguishi‐Tomita ex M.J Wynne. This latter species is thus conspecific with S. ptychoides and is therefore considered a heterotypic synonym thereof, as S. ptychoides has nomenclatural priority. This study expands the known geographical distribution of the species and may give insight into the origin of the species into other geographical regions.     

LECANORA COMPALLENS AND L. SINUOSA,TWO NEW OVERLOOKED CORTICOLOUS LICHEN SPECIES FROM WESTERN EUROPE

Lecanora compallens and L. sinuosa, two corticolous lichens, are described as species new to science on the basis of numerous collections. Lecanora compallens is a sorediate species, known only as sterile. It is probably common in Western Europe, but overlooked because it is very similar to L. expallens. Chemically, the new species is identical with L. strobilina, of which it may represent a sorediate counterpart. Lecanora sinuosa is a new species similar to L. chlarotera and so far only known from a limited area in the Netherlands and Germany, although it may be overlooked elsewhere. Lecanora sinuosa is very close to L. hybocarpa, with which it shares thepulicaris -type epihymenium inspersed with fine crystals but differs markedly by its thick thallus and thick and sinuous apothecium margin.     

Expression of amino acid transporter genes in developmental stages and adult tissues of Antarctic echinoderms

Epithelial cells in the body wall of adult and developmental stages of marine invertebrates absorb dissolved organic material directly from seawater. Despite over a century of study, little is known about the molecular biological mechanisms responsible for this transport process. Previous studies on embryonic and larval Antarctic echinoderms show that amino acid uptake could provide an important supplement of metabolic substrates. In the present study, partial cDNA sequences of 11 putative amino acid transporter genes were isolated from six species of Antarctic echinoderms including the Antarctic sea stars Acodontaster hodgsoni, Diplasterias brucei, Odontaster meridionalis, Odontaster validus, and Perknaster fuscus, and the Antarctic sea urchin Sterechinus neumayeri. Conserved domains of cDNA-deduced amino acid sequences characterized these genes as being members of a family of amino acid transporters (solute carrier family 6). Expression of these genes was detected throughout embryonic and larval development of two species that have contrasting developmental modes (A. hodgsoni: lecithotrophic; O. meridionalis: planktotrophic). In all six species studied, the expression of amino acid transporter genes was detected in tube feet and digestive organs of adult animals, demonstrating that members of a single amino acid transporter gene family are expressed during the entire life history of a marine invertebrate. The identification of these genes is an important step toward developing a mechanistic understanding of amino acid transport capacities in Antarctic marine invertebrates.