Gary B. Perlmutter

The Lichen Connections of Black Fungi

Many black meristematic fungi persist on rock surfaces—hostile and exposed habitats where high doses of radiation and periods of desiccation alternate with rain and temperature extremes. To cope with these extremes, rock-inhabiting black fungi show phenotypic plasticity and produce melanin as cell wall pigments. The rather slow growth rate seems to be an additional prerequisite to oligotrophic conditions. At least some of these fungi can undergo facultative, lichen-like associations with photoautotrophs. Certain genera presenting different lifestyles are phylogenetic related among the superclass Dothideomyceta. In this paper, we focus on the genus Lichenothelia, which includes border-line lichens, that is, associations of melanised fungi with algae without forming proper lichen thalli. We provide a first phylogenetic hypothesis to show that Lichenothelia belongs to the superclass Dothideomyceta. Further, culture experiments revealed the presence of co-occurring fungi in Lichenothelia thalli. These fungi are related to plant pathogenic fungi (Mycosphaerellaceae) and to other rock-inhabiting lineages (Teratosphaeriaceae). The Lichenothelia thallus-forming fungi represent therefore consortia of different black fungal strains. Our results suggest a common link between rock-inhabiting meristematic and lichen-forming lifestyles of ascomycetous fungi.

Bioassessing air pollution effects with epiphytic lichens in Raleigh, North Carolina, U.S.A.

Abstract Lichen diversity and coverage on willow oaks were measured in 16 parks in the Raleigh area of North Carolina, plus one natural area in nearby Orange County (control), as a pilot study for a potential statewide lichen biomonitoring project. This studys objectives were to assess the air pollution effects of the Raleigh urban airshed on these lichen communities, and determine what methods are best for this bioassessment. Thirty-one macrolichens and 24 crustose lichens were detected with average trunk floras of 4–20 taxa per site. Lichen communities were dominated by: Buellia curtisii, Candelaria concolor, Candelariella reflexa, Lecanora strobilina, L. hybocarpa, Physcia millegrana, Pyxine subcinerea and Punctelia rudecta, of which the macrolichen species are known to be pollution-tolerant, including Py. subcinerea, which is here described as such. The control site largely lacked these species, and harbored lichens more representative of nearby protected forests. All sites lacked pollution-sensitive beard lichens (Usnea spp.) and cyanolichens that are found in protected forests. Lichen Diversity Value (LDV) analysis of macrolichens did not result in the expected pattern of increasing diversity further away from the city center, due to a number of factors. However, negative correlations were found between lichen diversity variables and human population and traffic variables, as well as between tree trunk size and crustose lichen diversity. Macrolichen species richness and abundance were higher on mossy trunks, but crustose lichen diversity was lower. Bark texture and moisture as well as air quality appeared to influence the structure and composition of these lichen communities. In summary, the lichen communities on the urban trees appeared to be affected by the regions air pollution both in terms of diversity and species composition. Diversity measures are best tracked if the total community is measured, not just the macrolichen component. Crustose lichen coverage should also be incorporated in abundance studies.

Molecular data confirm the position of Flakea papillata in the Verrucariaceae

Abstract Flakea papillata is a predominantly tropical, widespread lichen characterized by flake-like thalli of narrowly arranged, irregularly wrinkled, small bluish-green lobes, whose taxonomic position was unclear. The lichen shows superficial similarity with either algal colonies, bryophytes or fern prothallia, but the production of zeorin and other triterpenoids supports its inclusion in the ascomycetes. Analysis of the nuclear large and small subunits rRNA sequence data of samples from different origins supports the position of F. papillata within the Verrucariaceae: it forms its own supported clade not related to the core of Agonimia, in which it has been previously placed.

Flakea papillata in North America

Abstract The distribution of Flakea papillata in North America is here reported from a survey of herbarium specimens. Unlike reported specimens from the tropics, North American F. papillata is primarily saxicolous with the first report on soil. Examined specimens were found in humid habitats near water.

Effects of highway pollution on forest lichen community structure in western Wake County, North Carolina, U.S.A.

Abstract We studied lichen communities along forest edge-to-interior gradients on opposite sides of a major highway and along a remote lakeshore in central North Carolina, U.S.A., to investigate highway pollution effects on this sensitive ecosystem component. At each site we sampled lichens on trees at 10 m intervals along each of five parallel transects established at the forest edge and at 25, 60, 100, and 150 m into the forest in the highway sites, with a similar layout along a nonlinear lakeshore in a similar forest type, from which transect distances from the forest edge were estimated using average tree distances from the nearest shoreline. Lichen communities were inventoried on tree trunks from the base up to 1.5 m height, then compared both among and within sites. Species richness was highest in the control site, and did not differ between the two highway sites. The highway sites were more similar to one another than either was to the control site, based on Bray-Curtis similarity indices. No associations were detected among sites and sampled lichen biotic components in terms of growth form, photobiont type or reproductive mode. In the highway sites, total transect species richness increased from the forest edge to 150 m distant. In the control site, species richness decreased from the forest edge to the most distant transect. Findings suggest a negative effect of highway pollution on species richness of lichen communities, but not on species composition by habit, photobiont type or reproductive mode. Despite the elevated NOx concentrations recorded along the highway, known nitrophilous species were largely absent, suggesting that other factors, including other pollutants, were affecting community structure near the highway.

Melaspilea demissa (Tuck.) Zahlbr. (lichenized Ascomycota) in eastern North America with a key to North American species of Melaspilea s. lat.

Recently collected specimens of the crustose lichen Melaspilea demissa from south-eastern USA have been compared with those of Melaspilea spp. previously determined from North America. A review of both the historical and contemporary treatments of this species is provided. A lectotype was selected from the type collection of M. demissa in FH and is here proposed as it best matches incomplete citations in the original treatment. We also discuss the nomenclatural and taxonomic status of the name Opegrapha cymbiformis var. deformis (considered a synonym of M. gibberulosa ). North American specimens of M. gibberulosa were found to be misidentifications, as were specimens attributed to M. lentiginosula , M. mesophlebia and M. octomera . We therefore recommend that these species be removed from the North American lichen checklist. We also present a key to North American Melaspilea .

Checklists of Corticolous Lichenized and Allied Fungi Collected in Mixed Forests of Western Wake County, North Carolina, USA

Abstract. Three checklist tables are presented from collections made during a study of corticolous lichen community response to highway pollution in western Wake County, North Carolina, USA. A total of 103 species of lichens and three species of allied fungi were found, representing 64 genera in 36 families. Two allied fungi, Amphisphaeria bufonia and Rebentischia massalongoi, are recommended to be added to the North American lichen checklist.

Noteworthy Collections of Lichens and Allied Fungi from Western Wake County, North Carolina, USA

Abstract. A seemingly undescribed Peltigera and several noteworthy collections were made during a gradient study examining highway effects on forest lichen communities in western Wake County, North Carolina, USA. Rebentischia massalongii is here newly reported from North Carolina. Acrocordia megalospora, Gyalolechia flavorubescens, and Porina scabrida are new records for the Piedmont ecoregion in the state. Lobaria quercizans is noteworthy as belonging to a group of pollution-sensitive cyanolichens that until recently have not been recorded from the Triangle area of central North Carolina. Historical occurrences of Triangle Lobariaceae are also presented.

Highway pollution effects on microhabitat community structure of corticolous lichens

Abstract We studied lichen communities on bole and base tree trunk segments along forest edge-to-interior gradients on opposite sides of a major highway and a control site in central North Carolina, U.S.A., to investigate if these two communities differ and if so, do they differ in response to highway pollution. At each site we measured various environmental parameters including ambient air NO2 concentrations, and sampled lichens on 5–7 trees along each of five parallel transects established at the forest edge and at 25, 60, 100 and 150 m into the forest. We compared lichen communities between the two trunk segments via species richness and composition by habit, photobiont type, and reproductive strategy. We then ran dual (bole and base) NMS ordinations with subsequent correlation/regression analyses to explore/test relationships of lichen parameters with environmental variables among the 15 sample transects combined. Species richness was similar between trunk segments at transect and site levels as well as overall. Bole and base communities were more compositionally similar to each other at the highway sites than they were at the control site, based on Bray-Curtis similarity indices (BC). Tree base communities differed in terms of functional groupings, with greater proportions of squamulose, cyanolichen and sterile species than found in tree bole communities, but varyingly so among sites. Patterns of bole-base BC values with distance from the forest edge were not apparent in any of the sites. Ordination analyses resulted in Axis 1 representing most of the variation for each trunk segment. Along this axis, correlations were similar between boles and bases, with the strongest ones involving lichen species richness (negative) and NO2 concentrations (positive); notably weak correlations involved tree species number, canopy cover and DBH. Similar patterns were found when lichen species number was correlated with environmental parameters directly, with NO2 concentration correlating strongest at each trunk segment. Among functional groups, % crustose and % fertile species on bases correlated significantly with NO2. Lichen species–NO2 relationships on boles and bases were both found to be highly significant quadratic relationships with base lichen richness being stronger.

Is Stirtonia alba in North America? Resolving a nomenclatural impasse and assessing the taxonomic status of the Arthonia alba complex

Abstract The invalid combination Stirtonia alba (Müll. Arg.) ined., based on Arthonia alba Müll. Arg., is listed for the continental United States in several important online repositories, including CNALH, USDA PLANTS and EOL. Although Arthonia alba belongs in Stirtonia, the name cannot be used in that combination, as it is blocked by S. alba Groenh. ex Makhija & Patw., a species described from Java, Indonesia, and both taxa are distinct morphologically, anatomically and chemically. Here, we resolve this nomenclatural impasse by proposing the new name S. caribaea for A. alba. We examined further material identified as “A. alba / S. alba” from North America and the Caribbean. Specimens ascribed to “S. alba (Müll. Arg.) ined.” from North America (Louisiana, Florida) were found to be misidentifications in other genera, with only one collection confirmed as a Stirtonia. This specimen was determined to be S. punctiformis, and is here reported as new to North America, representing a northward range extension from Central America and northern South America. Therefore, the name “Arthonia alba Müll. Arg.” listed under Stirtonia in the North American lichen checklist should be removed. Caribbean material previously identified as A. alba was found to represent two species: A. alba s.str., here renamed S. caribaea, known from Cuba and St. John of the U.S. Virgin Islands; and S. borinquensis, which we describe as a new species from Puerto Rico.