Calvitimela is a fungal genus in the family Tephromelataceae, comprising 11 species of lichen. These lichens grow tightly attached to rocks, appearing as thin, crust-like layers on their surface. They are primarily found in alpine and arctic regions around the world. Calvitimela species are characterised by their areolate (segmented) thallus and black, shiny, convex apothecia (fruiting bodies). The genus currently includes eleven recognised species, though recent genetic studies have revealed unexpected diversity within this group. Calvitimela lichens are known for their varied secondary metabolites, which can sometimes aid in species identification. However, the taxonomy of the genus remains complex and challenging, with ongoing research uncovering new information about their relationships, distribution, and evolution. These lichens play important ecological roles in their harsh mountain and polar habitats, where they are often among the few organisms able to thrive.
The taxonomic history of Calvitimela is long and relatively complex.[1] In the early days, the species now belonging to Calvitimela were placed in the classical genus Lecidea Ach., e.g. by Fries (1874; as Lecidea stirps L. armeniacae).[2] and Magnusson (1931; as "Lecidea armeniaca- und elata-Gruppe")[3] In the 1980s, several taxonomists revised large groups of lichens in Lecanora and Lecidea.[4][5] First, the generic name Tephromela was resurrected, and the new monotypicfamilyTephromelataceae described.[4] Then, a group from Lecidea was moved into the genus Tephromela M. Choisy.[5] This led to species with both lecanorine and lecideine apothecia being present in the same genus.[5] Finally, the genus Calvitimela was erected for species with lecideine apothecia previously placed in Tephromela.[4]
Recent molecular phylogenetic studies have revealed that the taxonomy of Calvitimela is more complex than previously thought.[6] The genus is now understood to be paraphyletic, with its subgenera and the genus Violella forming deeply divergent lineages that originated about 35 million years ago. The family Tephromelataceae consists of the genera Tephromela, Calvitimela, Mycoblastus and Violella, which together constitute a well-supported monophyletic group.[7][8] However, resolving the deep phylogenetic relationships within Tephromelataceae has proven challenging, possibly due to incomplete lineage sorting or substitutional saturation.[6]
Within Calvitimela, molecular studies have identified four distinct lineages in the subgenus Calvitimela, corresponding to C. armeniaca, C. melaleuca I, C. melaleuca II, and the newly recognized C. melaleuca III. This renders C. melaleuca, as traditionally circumscribed, paraphyletic. Additionally, a new clade sister to C. aglaea has been discovered within the subgenus Severidea.[6]
The current taxonomic placement of Calvitimela presents challenges for classification. Options include accepting a paraphyletic Calvitimela, lumping all species in Calvitimela, Tephromela, and Violella into a broad Tephromela, or raising the current subgenera to generic rank. Each option has its drawbacks, and further research is needed to resolve these taxonomic issues.[6]
Description
Calvitimela perlata
The species of Calvitimela are crustose lichens. Their thallus are areolate and their apothecia lecideine. The apothecia are convex, black and shiny.[9]Apothecia are rare or entirely absent in some sorediate species e.g. C. cuprea, C. livida[8] and C. talayana.[9]
Asci are generally of the Lecanora-type,[4][10] but Bacidia-type asci are also observed in C. aglaea and C. perlata.[8] The spores are usually simple and ellipsoid.[9]
Recent studies have revealed that thallus colour can be a diagnostic character for fresh specimens of C. melaleuca lineages. C. melaleuca I exhibits white to light brown thallus colour, C. melaleuca II shows yellow to brownish-yellow thallus colour, and C. melaleuca III has a beige coloured thallus.[6]
Spore size has been found to be an important morphological character. C. perlata has significantly larger spores compared to other taxa in Calvitimela. The sister taxa C. melaleuca II and C. armeniaca have been observed to have narrower spores compared to other species in the genus.[6]
An esorediate and fertile morphotype of C. cuprea has been discovered, extending the morphological range of this species. This finding implies that different reproductive strategies can occur within the same species of Calvitimela.[6]
There is much chemical variation of secondary metabolites in the species of Calvitimela. Most prominently observed in the C. melaleuca – complex, with alectorialic, norstictic, roccellic and psoromic acids occurring in different combinations in the species´ several chemotypes.[8] Recent studies have shown that the chemical profiles within subgenus Calvitimela are complex and overlapping, making it challenging to use chemistry as a diagnostic tool at the species level.[6]
In the subgenus Severidea, C. aglaea is distinguishable from other species by containing bourgeanic acid and usnic acid. Other species in this subgenus share atranorin and stictic acid as major compounds.[6]
The overall chemosyndrome in each subgenus of Calvitimela is distinct, making it informative at higher taxonomic levels. However, within subgenera, especially in subgenus Calvitimela, chemical characters are often homoplastic at the species level.[6]
Ecology and distribution
All species of Calvitimela grow on rocks. The species in Calvitimela reside either on boulders of varying size or directly on mountainous walls and are occasionally found on pebbles. A peculiar ecological preference is observed in C. cuprea. This species is more or less morphologically identical to C. livida, but seem to only grow on copper rich rocks, and is associated with old copper mine localities.[8]
Species in Calvitimela are predominantly distributed in alpine to arctic regions, and they seem to have a circumpolar distribution.[9] On the other hand, due to lack of sampling in certain regions of the world (e.g. Africa, Asia and South America), the true distribution of Calvitimela is only partly known. C. austrochilensis is described from Chile [10] and C. uniseptata from Antarctica,[11] respectively. These species have not yet been included in any molecular phylogenetic studies. Therefore, whether they belong in Calvitimela or not, is yet to be confirmed by molecular data.
Recent studies have provided more detailed insights into the ecology and distribution of Calvitimela species:[6]
The different lineages of C. melaleuca (I, II, and III) show potential altitudinal preferences. C. melaleuca II and a subclade of C. melaleuca I appear to be connected to higher elevations, while C. melaleuca I seems to be more widely distributed at lower altitudes in Norway. C. cuprea has been confirmed to have a strong association with heavy metal-rich substrates, particularly copper. However, it has been noted that some individuals have been collected outside of mining habitats, suggesting a wider ecological tolerance than previously thought. The ecological distinction between C. cuprea and C. livida has been further clarified. While C. cuprea is primarily associated with heavy metal rocks, C. livida has a wider habitat range. The newly discovered clade sister to C. aglaea (referred to as C. sp.) was found to be morphologically similar to C. perlata, highlighting the importance of molecular data in understanding species distributions and ecology.
The circumpolar distribution of Calvitimela has been further supported by recent sampling efforts. However, it has been emphasized that more extensive sampling, particularly in understudied regions such as Africa, Asia, and South America, is needed to fully understand the global distribution patterns of these lichens.[6]
The discovery of cryptic diversity within Calvitimela, particularly in Norway, suggests that there may be significant undiscovered diversity at a global level. This underscores the need for more comprehensive sampling and molecular studies to fully elucidate the ecological niches and distribution patterns of Calvitimela species worldwide.[6]
Phylogeny
Molecular phylogenetics has revolutionised the taxonomy of crustose lichens and revealed an extensive amount of cryptic speciesdiversity.[12] In Calvitimela there are some species that are morphologically identical, but are genetically distinct and have different chemotypes.[8] In the C. melaleuca–complex at least two distinct chemical lineages are observed [8] with no currently known morphological correlation.
Recent phylogenetic analyses have significantly expanded our understanding of Calvitimela.[6] The subgenus Calvitimela now comprises four supported clades: C. armeniaca, C. melaleuca I, C. melaleuca II, and the newly recognised C. melaleuca III. This discovery renders C. melaleuca, as traditionally circumscribed, paraphyletic with respect to C. armeniaca.[6]
Within the subgenus Severidea, C. aglaea has been shown to be genetically heterogeneous, with three highly supported groupings and one moderately supported grouping. A new clade, sister to C. aglaea, has also been discovered in this subgenus.[6]
There have been few studies investigating Calvitimela from a molecular phylogenetics perspective.[7][8] Only one phylogeny focusing exclusively on Calvitimela has been published.[8] They found Calvitimela, Tephromela and Violella to constitute a well-supported monophyletic group. The relationship between the main clades remained partly unresolved, however. No study has yet included all species currently circumscribed to Calvitimela, but the genus is so far indicated to be paraphyletic.[7][8]
Challenges in resolving deep phylogenetic relationships within Tephromelataceae persist, possibly due to incomplete lineage sorting or substitutional saturation. Molecular dating estimates suggest that the major lineages in Calvitimela and Violella diverged about 35 million years ago, indicating they represent relatively old evolutionary lineages.[6]
The phylogenetic placement of two Southern Hemisphere species, C. austrochilensis and C. uniseptata, remains uncertain. Molecular evidence suggests that C. uniseptata may belong to the genus Lecania rather than Calvitimela.[6]
Future phylogenetic studies may benefit from whole-genome sequencing approaches and broader taxon sampling to better resolve the evolutionary relationships within Calvitimela and the Tephromelataceae.[6]
The Acarosporaceae are a family of fungi in the order Acarosporales. Members of this family have a widespread distribution, and are mostly lichenized with green algae. According to a 2021 estimate, the family contains 11 genera and about 260 species. The family is characterised by a hamathecium formed of paraphysoids.
The Baeomycetales are an order of mostly lichen-forming fungi in the subclass Ostropomycetidae, in the class Lecanoromycetes. It contains 8 families, 33 genera and about 170 species. As a result of molecular phylogenetics research published in the late 2010s, several orders were folded into the Baeomycetales, resulting in a substantial increase in the number of taxa.
Fuscideaceae is a family of fungi that form symbiotic relationships with algae to create lichens. These lichens typically have a crust-like appearance and are found worldwide, though they are most common in temperate regions. The family includes five genera and about 55 species, which primarily grow on tree bark, rocks, or occasionally on wood or leaves. Fuscideaceae lichens are characterised by their reproductive structures, cup-like formations called apothecia, which can vary in colour from red to dark brown or black. The family has undergone several changes in its classification over the years, with recent genetic studies placing it within the order Umbilicariales. Fuscideaceae lichens produce various chemical compounds, some of which are unique to this family, and these chemicals are often used to help identify different species.
The Lecideaceae are a family of lichen-forming fungi in the order Lecideales. It contains about 30 genera and roughly 250 species. A major distinguishing characteristic of the family is the lecanoroid form of the fruiting bodies: typically circular, dark, and without a thalline margin. Most species in the family are lichenised with green algae, although a few species, scattered amongst several genera, are lichenicolous—they live on other lichens. Lecideaceae lichens tend to grow on rocks, wood, and soil. Several Lecideaceae species accelerate the weathering of rock surfaces, a process known as pedogenesis, by extending their hyphae into cracks and expelling rock flakes. This contributes to significantly faster weathering rates in certain environments, impacts various materials from natural rocks to man-made Sekishu roof tiles, and involves key biomolecules identified for survival and biodeterioration, including compounds to withstand intense ultraviolet radiation.
Rhizocarpon is a genus of crustose, saxicolous, lecideoid lichens in the family Rhizocarpaceae. The genus is common in arctic-alpine environments, but also occurs throughout temperate, subtropical, and even tropical regions. They are commonly known as map lichens because of the prothallus forming border-like bands between colonies in some species, like the common map lichen.
Hypocenomyce is a genus of lichen-forming fungi in the family Ophioparmaceae. Species in the genus grow on bark and on wood, especially on burned tree stumps and trunks in coniferous forest. Hypocenomyce lichens are widely distributed in the northern hemisphere.
Tephromela is a genus of lichens in the family Tephromelataceae. There are about 25 species in this widespread genus.
Mycoblastus is a genus of crustose lichens in the family Tephromelataceae. Members of the genus are commonly called blood lichens.
The Tephromelataceae are a family of lichenized fungi in the order Lecanorales. The family was circumscribed by Austrian lichenologist Josef Hafellner in 1984. Tephromelataceae comprises the genera Tephromela, Calvitimela, Mycoblastus and Violella, which together constitute a well-supported monophyletic group.
Schaereria is a genus of lichen-forming fungi. It is the sole genus in the family Schaereriaceae, which itself is the only family in the Schaereriales, an order in the subclass Ostropomycetidae of the class Lecanoromycetes. Most Schaereria species are crustose lichens that live on rocks. Schaereria was first proposed by Gustav Wilhelm Körber in 1855 and was later taken up by other lichenologists despite periods of disuse.
Sporastatiaceae is a small family of crustose lichens in the order Rhizocarpales. It contains two genera, Sporastatia and Toensbergia, with a total of five species. Sporastatiaceae was circumscribed in 2013 by Mika Bendiksby and Ernst Timdal.
The Rhizocarpales are an order of lichen-forming fungi in the subclass Lecanoromycetidae of the class Lecanoromycetes. It has two families, Rhizocarpaceae and Sporastatiaceae, which contain mostly crustose lichens.
Sporastatia is a genus of crustose lichens in the family Sporastatiaceae. It has four species. Sporastatia lichens are long-lived species that grow on siliceous or weakly calcareous rocks in arctic and alpine locales.
Porpidinia is a genus of lichen-forming fungi in the family Lecideaceae. It has two species of saxicolous (rock-dwelling) lichens. The type species of the genus, Porpidinia tumidula, thrives in a variety of settings from coastal to mountainous areas, primarily on lime-rich rocks, and is widely spread across southern to northern Europe, northern Africa, parts of Asia, and New Zealand. Meanwhile, Porpidinia brevispora is more regionally confined, found specifically in the Sikhote-Alin range in the Russian Far East, favouring carbonate rocks at lower altitudes.
Fulgidea is a genus of lichen-forming fungi in the family Umbilicariaceae. It has two species of squamulose lichens that grow on bark and on wood.
Lecidea toensbergii is a species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. Described as a new species in 2018, it has been documented from several locations in Norway and a single location in Sweden, where it grows in rocky alpine environments.
Mycoblastus sanguinarius, commonly known as the bloody heart lichen, is a widespread species of crustose lichen in the family Tephromelataceae. It is distinguished by its pale to dark grey thallus, which can appear very irregular and uneven, often with a thick, coarse, wart-like texture. The thallus may be continuous or somewhat cracked, with a prothallus that ranges from pale to dark grey. The apothecia are frequent, black, and become convex or hemispherical as they mature. These structures develop on a bright carmine-red thalline cushion, which is revealed when the thallus is damaged or worn. The lichen grows in temperate and montane forests across Asia, Europe, and North America. Usually found on tree bark, it has been recorded less frequently on decorticated wood and moss-covered rocks.
Puttea is a genus of lichen-forming fungi with uncertain familial placement in the order Lecanorales. The genus comprises four species. Finnish lichenologists Soili Stenroos and Seppo Huhtinen established the genus Puttea in 2009 for the lichen species formerly known as Lecidea margaritella, which has undergone various reclassifications. Molecular phylogenetics analyses have shown that Puttea margaritella does not align closely with genera like Fellhanera or Micarea, but its precise familial placement remains uncertain. Puttea is characterized by an indistinct, lichenized thallus composed of delicate fungal filaments and small algal cells. Its minute, round, whitish apothecia lack a distinct margin, and the asci, or spore-producing cells, are thick-walled, club-shaped, and contain eight spores, showing specific reactions with iodine-based stains. The type species of the genus, Puttea margaritella, typically inhabits boreal forests, growing on the liverwort species Ptilidium pulcherrimum and sometimes on decaying wood or bark. Initially thought to be confined to Europe, it has since been found in North America, particularly in Alaska and Québec, extending its known range. The species is parasitic, damaging its host, and is considered rare within its distribution.
Romjularia is a fungal genus in the family Lecideaceae, containing the single species Romjularia lurida, a saxicolous and terricolous squamulose lichen.
Boreoplaca is a fungal genus in the family Ophioparmaceae. It comprises the single species Boreoplaca ultrafrigida, a saxicolous (rock-dwelling), squamulose lichen. Both the genus and species were described in 1994 by the Norwegian lichenologist Einar Timdal. The lichen is found in Eastern Siberia, the Russian Far East as well as in adjacent territories of north-east China, and in South Korea. The main characteristics of the lichen are its squamulose thallus, black lecideine apothecia, and Fuscidea-type asci.
↑ Fries, T. M. (1874). Lichenographia Scandinavica 1, 2. Uppsala: E. Berling.
↑ Magnusson, A. H. (1931). "Studien Über Einige Arten der Lecidea armeniaca- und Elata-Gruppe". Acta Horti Gothoburg. 6: 93–144.
1 2 3 4 Hafellner, Josef (1984). "Studien in Richtung Einer Natürlicheren Gliederung der Sammelfamilien Lecanoraceae und Lecideaceae". Beihefte zur Nova Hedwigia: 241–371.
1 2 3 Hertel, Hannes; Rambold, Gerhard (1985). "Lecida Sect. Armeniacae: Lecideoide Arten der Flechtengattungen Lecanora und Tephromela (Lecanorales)". Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Fjelde, Markus Osaland; Timdal, Einar; Haugan, Reidar; Bendiksby, Mika (2024). "Paraphyly and cryptic diversity unveils unexpected challenges in the "naked lichens" (Calvitimela, Lecanoromycetes, Ascomycota)". Molecular Phylogenetics and Evolution. 190: 107944. doi:10.1016/j.ympev.2023.107944.
1 2 3 4 5 6 7 8 9 10 Bendiksby, Mika; Haugan, Reidar; Spribille, Toby; Timdal, Einar (2015). "Molecular phylogenetics and taxonomy of the Calvitimela aglaea Ccomplex (Tephromelataceae, Lecanorales)". Mycologia. 107 (6): 1172–1183. doi:10.3852/14-062. PMID26354804.
1 2 3 4 Haugan, R.; Timdal, E. (1994). "Tephromela perlata and T. talayana, with notes on the T. aglaea-complex". Graphis Scripta. 6: 17–26.
1 2 Fryday, Alan (2011). "New species and combinations in Calvitimela and Tephromela from the southern subpolar region". The Lichenologist. 43 (3): 225–239. doi:10.1017/S0024282911000065.
↑ Thor, G (2011). "Calvitimela uniseptata G. Thor sp. nov". Phytotaxa. 18: 36.
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