| Pachnolepia | |
|---|---|
 | |
| Pachnolepia pruinata | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Arthoniomycetes |
| Order: | Arthoniales |
| Family: | Arthoniaceae |
| Genus: | Pachnolepia A.Massal. (1855) |
| Type species | |
| Pachnolepia pruinata (Torss.) Frisch & G.Thor (2014) | |
| Species | |
Pachnolepia is a small fungal genus in the family Arthoniaceae. [1] [2] It comprises two species of corticolous (bark-dwelling) lichens.
Pachnolepia was originally circumscribed by the Italian lichenologist Abramo Bartolommeo Massalongo in 1855. [3] The genus was resurrected for use in 2014 as part of a molecular phylogenetics-informed reorganisation of the Arthoniaceae. [4]
The original type species of the genus, Pachnolepia impolita (now known as P. pruinata ), was designated by Sundin et al. in 2012. [5] Molecular studies revealed that this species occupies an isolated position within the cryptothecioid subclade, distinct from Arthonia radiata , supporting its recognition as a separate genus. [4]
In a later phylogenetic analysis, Pachnolepia pruinata was shown to have a sister placement to Arthothelium spectabile , and both of these species form a clade that is sister to a clade contain two Tylophoron species. [6]
A second species was added to the genus in 2024, when André Aptroot and colleagues described the species Pachnolepia longipseudisidiata , a lichexanthone-containing Brazilian endemic featuring long pseudoisidia . They noted, however, that "It is probably only distantly related to the type of the genus, so placement in a new genus in the future is to be expected". [7]
Species of Pachnolepia form crustose lichens with distinctive morphological features. The thallus is typically effuse (spread out on the substrate), continuous, and can be whitish to pale grey or pale brown in colour. Surface texture varies from matt or powdery to somewhat verrucose , with thickness ranging from very thin (< 0.1 mm) to occasionally warty and up to 1 mm thick. The genus includes both fertile and sterile species. [8] [7]
When present, apothecia are up to 1 mm in diameter, rounded or angular, and may be elongated or somewhat stellate . They are characteristically immersed in the thallus and often appear inconspicuous when dry due to thick white pruina . The internal structure includes a red-brown epithecium that turns grey or pale green in potassium hydroxide solution (K), a colourless hymenium 40–60 μm tall, and numerous paraphysoid s. Ascospore s, when present, are cylindric to obovoid in shape, and usually contain 4 or 5 septa. They are colourless (hyaline) and measure 13–22 by 4.5–7 μm. [8]
Some species produce reproductive structures other than apothecia, such as pseudoisidia, which can be cylindrical to gnarled and unbranched. The photobiont is trentepohlioid across the genus. [7]
Members of the genus Pachnolepia are corticolous, growing on the bark of trees. In Europe, P. pruinata shows a preference for rain-sheltered, dry bark of tree trunks in nutrient-enriched situations, particularly favouring species such as Maple, Ash, and Oak. It can become locally dominant on tree trunks and is occasionally found on wooden boards and dry stonework. The species is frequent in southern Britain, extending locally to southern Aberdeenshire, while being uncommon and primarily eastern in distribution in Ireland. [8]
In South America, P. longipseudisidiata has been documented in mountain forest habitats of Brazil, specifically in the Chapada Diamantina region, where it occurs at elevations of around 1,100 m (3,600 ft). [7]
The Arthoniales is the second largest order of mainly crustose lichens, but fruticose lichens are present as well. The order contains around 1500 species, while the largest order with lichenized fungi, the Lecanorales, contains more than 14000 species.
The Arthoniaceae are a family of lichenized, lichenicolous and saprobic fungi in the order Arthoniales. The Arthoniaceae is the largest family of Arthoniales, with around 800 species. Most species in Arthoniaceae belong in Arthonia which is the largest genus with 500 species. The second and third largest genus is Arthothelium with 80 species, and Cryptothecia with 60 species.
Arthothelium is a genus of lichen-forming fungi in the family Arthoniaceae.
Arthonia is a genus of lichens in the family Arthoniaceae. It was circumscribed by Swedish botanist Erik Acharius in 1806.
Felipes is a genus of lichenized fungi in the order Arthoniales. Circumscribed by Andreas Frisch and Göran Thor in 2014, it contains the single species Felipes leucopellaeus. Genetic analysis shows that the genus falls into the order Arthoniales, but its familial placement is uncertain. Felipes leucopellaeus is found across Europe and North America in temperate and boreal regions, typically in old-growth forest or wooded mires. It is crustose and corticolous.
Tylophoron is a genus of lichen-forming fungi in the family Arthoniaceae. It comprises seven species of crustose lichens, most of which occur in tropical regions.
Sagenidiopsis isidiata is a species of corticolous (bark-dwelling) byssoid lichen in the family Arthoniaceae. Found in tropical montane rainforests throughout Central America, South America, and the Antilles, it was described as new to science in 2011. The lichen is characterised by its cream-coloured to greyish thallus and numerous pseudoisidia, which are small, cylindrical outgrowths on its surface.
Briancoppinsia is a fungal genus in the family Arthoniaceae. It is monotypic, containing the single species Briancoppinsia cytospora, a lichenicolous fungus that parasitises parmelioid lichens, as well as Cladonia, Lepra, and Lecanora conizaeoides, among others. The species was first described scientifically by Léon Vouaux in 1914 as Phyllosticta cytospora.
Inoderma is a genus of lichen-forming fungi in the family Arthoniaceae. It was resurrected for use in 2015 for a small group of species with the following features: elevated, white pruinose pycnidia, immersed to adnate white pruinose apothecia, and a weakly gelatinized hymenium. Inoderma byssaceum was assigned as the type species for the genus.
Bryostigma is a genus of fungi of uncertain familial placement in the order Arthoniales. The genus is characterised by its thin, patchy growth that either partially embeds into its growing surface or forms an irregular, granular surface, with distinctive red or blue iodine staining of its hyphae and very small fruiting bodies. Most Bryostigma species are parasitic (lichenicolous), growing on other lichens, though a few species like B. lapidicola grow independently on stone or moss. While the genus was initially established with a single species growing on moss, it was significantly expanded in 2020 when several species were transferred from the related genus Arthonia based on DNA analysis, though this taxonomic reclassification has been subject to some scientific dispute. As of 2024, the genus includes seventeen species – thirteen parasitic and four independent lichen species.
Reichlingia is a genus of lichen-forming fungi in the family Arthoniaceae. It has seven species. The genus was originally circumscribed by Paul Diederich and Christoph Scheidegger in 1996, with Reichlingia leopoldii as the type, and at that time, only species. The fungus was at first thought to be a lichenicolous (lichen-dwelling) fungus, but is now considered a lichenised hyphomycete.
Arthonia isidiata is a species of corticolous (bark-dwelling) crustose lichen in the family Arthoniaceae. Found in Central America, it is characterized by its thin, shiny thallus, and isidia that emerge from the surface. Discovered in Costa Rica's Corcovado National Park, and later recorded from Panama, this species thrives in lowland tropical coastal rainforests on smooth bark of smaller, often young trees.
Sporodophoron is a genus of lichen-forming fungi in the family Arthoniaceae. It includes four corticolous (bark-dwelling) crustose lichen species. Sporodophoron is uniquely characterised by the formation of fruiting structures called sporodochia, which are open conidiomata in the form of tufts of conidiophores on the thallus. Although these lichens bear a strong resemblance to Inoderma, another genus within the same family, Sporodophoron's distinct chemical makeup sets it apart from its lichen relatives. Collectively, the genus has a widespread geographical distribution in the Northern Hemisphere, with species found in distinct habitats in North America, Europe, Japan, and the Russian Far East.
Coniocarpon is a genus of lichen-forming fungi in the family Arthoniaceae. It has eight species of corticolous (bark-dwelling) lichens. This genus is distinct for its crystalline orange, red, and purple quinoid pigments in the ascomata that turn purple in potassium hydroxide solution, its colourless, transversely septate ascospores with large apical cells, and its rounded to lirellate ascomata.
Glomerulophoron is a small genus of lichen-forming fungi in the family Arthoniaceae. The genus contains two species of corticolous (bark-dwelling) crustose lichens. It was circumscribed in 2015 by the lichenologists Andreas Frisch, Damien Ertz, and Göran Thor. It was created to contain a single species from Mauritius, G. mauritiae, which was distinct from the similar genus Sporodophoron both genetically and morphologically, in the tightly coiled chains of sporodochial conidia. The genus gained another member in 2024 when the Brazilian species G. confluentisorediatum was added to it. It is distinguished from the type species by the absence of sporodochia.
Arthonia thoriana is a species of bark-dwelling fungus in the family Arthoniaceae. It is found in the grazed pasture woodlands of Somerset, Great Britain.
Snippocia is a monospecific fungal genus in the family Arthoniaceae. It contains the single species Snippocia nivea, a crustose, corticolous (bark-dwelling) lichen. This lichen was previously known as Schismatomma niveum; Snippocia was established to accommodate the species after molecular studies indicated that it did not belong in its previously assigned genus.
Leprantha is a fungal genus in the family Arthoniaceae. It comprises a single species, Leprantha cinereopruinosa, a corticolous (bark-dwelling), crustose lichen.
Arthonia radiata, the asterisk lichen, is a common and widepspread species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae.
Diarthonis is a fungal genus in the family Graphidaceae. Originally created in 1909 but long unused, the genus was revived in 2020 to accommodate D. spadicea when molecular studies showed this species fell outside the main Arthonia clade. The species grows as a thin, greyish to greenish crust beneath tree bark, producing small black disc-like reproductive structures (apothecia) that resemble drops of tar. It is considered an indicator of ecological continuity in old-growth broadleaved forests, particularly those dominated by English oak, and is listed as near-threatened in some regions.