Teloschistaceae

Teloschistaceae
Teloschistes flavicans is the type species of the type genus of the family Teloschistaceae.
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Teloschistales
Family:	Teloschistaceae Zahlbr. (1898)
Type genus
Teloschistes Norman (1853)
Subfamilies
Caloplacoideae – 37 genera Teloschistoideae – 33 genera Xanthorioideae – 45 genera
Synonyms
Caloplacaceae Zahlbr. (1907)

The Teloschistaceae are a large family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. Many members of the Teloschistaceae are readily identifiable by their vibrant orange to yellow hue, a result of their frequent anthraquinone content. The presence of these anthraquinone pigments, which confer protection from ultraviolet light, enabled this group to expand from shaded forest habitats to harsher environmental conditions of sunny and arid ecosystems during the Late Cretaceous. Collectively, the family has a cosmopolitan distribution, although members occur predominantly in subtropical and temperate regions. Although most members are lichens that either live on rock or on bark, about 40 species are lichenicolous fungi–meaning they live on other lichens.

Teloschistaceae lichens typically have one of a few physical growth forms. Depending on the species, the thallus (the main body of the lichen) is either leaf-like (foliose), bushy or shrub-like (fruticose) or crust-like (crustose). These lichens typically partner with a photosynthetic companion (a photobiont) from the green algal genus Trebouxia or similar genera. Teloschistaceae members are also characterised by their apothecia (the fruiting bodies where sexual reproduction occurs), which generally have well-defined encircling rim of tissue, contributing to the lichen's overall structure and appearance. A distinct feature of Teloschistaceae is the bluish reaction of the ascus tip's external layer to iodine – the ascus being the spore-producing structure. The ascospores are released through a longitudinal slit in the tip of the ascus, a unique trait common to this group of lichens.

The family, first formally proposed in 1898, was extensively revised in 2013, including the recognition of three distinct subfamilies (Caloplacoideae, Teloschistoideae, and Xanthorioideae), and the creation or resurrection of 31 genera. Since 2013, several dozen new genera have been added to the family, but there has been some debate about these additions. Ongoing DNA studies are helping to provide clearer insights into how the different groups within this family are related. Depending on the source consulted, the family is estimated to contain up to more than 1000 species and 117 genera. Three species from the Teloschistaceae have been globally assessed for conservation status, with others appearing on regional lists, such as the rare New Zealand species Caloplaca allanii. The full diversity of this family remains underexplored in vast regions like South America and China.

Systematics

Historical taxonomy

The common and widespread Teloschistaceae species Xanthoria parietina (left) and Teloschistes chrysophthalmus (right) were two of the earliest lichens to be formally described.

The first members of the present-day Teloschistaceae to be formally described were the common sunburst lichen (Xanthoria parietina) and the gold-eye lichen (Teloschistes chrysophthalmus). These were two of several dozen lichen species described by Swedish taxonomist Carl Linnaeus, the former in his influential 1753 treatise Species Plantarum, and the latter in his 1771 work Mantissa Plantarum II.

In his 1852 work Synopsis Lichenum Blasteniosporum ("Synopsis of Lichen Blasteniospores"), Italian lichenologist Abramo Bartolommeo Massalongo attempted to classify what he called "blasteniospore lichens". This term referenced species, diverse in growth forms and appearance, united by the distinct polarilocular spores now attributed to the family Teloschistaceae. These are spores that are divided into two compartments (locules) separated by a central septum with a perforation. Although Massalongo's efforts to arrange these taxa into more natural genera were largely ignored by later contemporaries, several of his proposed genera were resurrected for use 16 decades later, such as Blastenia, Gyalolechia, Pyrenodesmia, and Xanthocarpia.

An ascus of the crustose lichen Pyrenodesmia variabilis, containing eight polarilocular ascospores.

The family Teloschistaceae was formally circumscribed by lichenologist Alexander Zahlbruckner in 1898. In his initial version, he grouped together foliose and fruticose taxa having polarilocular (i.e. two-locule) or four-locule ascospores, including the genera Xanthoria, Teloschistes, and Lethariopsis. At that time, the growth form of the lichen thalli was often used in classical lichen taxonomy to segregate groups of species into families, and so in a subsequent (1926) publication, Zahlbruckner introduced the family Caloplacaceae to contain crustose lichens with polarilocular ascospores; this family included the genera Caloplaca, Blastenia, Bombyliospora, and Protoblastenia. However, the distinctness of the family Caloplacaceae was largely rejected by other authors, and it is now a historical synonym of Teloschistaceae. In another older classification, crustose genera were grouped together in the family Blasteniaceae or the Placodiaceae. In 1971, Carroll William Dodge proposed the family Xanthoriaceae to contain Xanthodactylon, Xanthopeltis and Xanthoria, but it was not validly published.

In the 20th century, particularly with the widespread use of electron microscopy, the details of ascus structure became quite important considerations in the taxonomy of lichen-forming fungi. In the case of the Teloschistaceae, several studies on various species noted the common presence of a strongly amyloid cap-like zone at the tip of the ascus. Rosmarie Honegger, using transmission electron microscopy to better visualise structure, verified the presence of a special ascus type featuring an amyloid outer layer without visible apical structures, and with an irregular dehiscence; she named this the Teloschistes-type. The presence of this ascus type was later used as a diagnostic character for the family Teloschistaceae following an ultrastructural study that corroborated her work. In 1989, Ingvar Kärnefelt revised the family, accepting ten genera, and this served as the main taxonomic classification for the family until the molecular era. In one of the last classifications of the family prior to the widespread use and implementation of molecular techniques, Ove Eriksson, in his popular Outline of the Ascomycota series, accepted 12 genera in Teloschistaceae in 2006: Caloplaca, Cephalophysis, Fulgensia, Huea, Ioplaca, Josefpoeltia, Seirophora, Teloschistes, Xanthodactylon, Xanthomendoza, Xanthopeltis, and Xanthoria. The family continues to undergo significant changes. For example, in 2020, of all fungal families, Teloschistaceae had the fourth-highest number of new fungal names (a total of 128), including 8 genera, 48 new species and infraspecific taxa, and 72 new combinations.

Etymology

As is standard practice in botanical nomenclature, the name Teloschistaceae is based on the name of the type genus, Teloschistes, with the ending -aceae indicating the rank of family. The genus name, assigned by Norwegian botanist Johannes M. Norman in 1852, comprises two Greek words: τέλος (télos), meaning "end", "final", or "term"; and σχιστός (-schistós), meaning "divided into", "split", or "separated". It refers to the split ends of the thallus branches that are characteristics of that genus.

Subfamilial and ordinal classification

Teloschistales Teloschistaceae Teloschistoideae Hosseusiella Tassiloa Villophora Teloschistes Josefpoeltia Stellarangia Kaernefia 'Caloplaca' sp.5 Andina Sirenophila Elixjohnia Haloplaca Teloschistopsis Brownliella Neobrownliella Filsoniana Nevilleiella Aridoplaca Follmannia Harusavskia Wetmoreana Scutaria Cinnabaria Catenarina Xanthorioideae Shackletonia Pachypeltis Parvoplaca Xanthomendoza Squamulea Huriella Amundsenia Xanthocarpia Cerothallia Gondwania Austroplaca Xanthopeltis Teuoahtiana Charcotiana Flavoplaca Calogaya Orientophila Xanthoria Dufourea Athallia Solitaria Polycauliona Caloplacoideae  'Caloplaca' brebissoni Teuvoahtiana Franwilsia Eilifdahlia 'Caloplaca' spp. 1 & 2 Gyalolechia 'Calopaca' lecanorocarpa 'Calopaca' lecapustulata Huneckia 'Caloplaca' quadrilocularis Blastenia Bryoplaca Kuettlingeria furax Rufoplaca Usnochroma Seirophora Variospora Caloplaca Leproplaca Kuettlingeria atroflava Kuettlingeria albolutescens Pyrenodesmia Olegblumia dismissa Brigantiaeaceae Brigantiaea sp. Letroutia vulpina

Cladogram showing the phylogeny of some species and genera in family Teloschistaceae and in the order Teloschistales; based on analysis by Wilk et al. in 2021 (simplified from original). Species names have been updated to reflect current taxonomy. Single quote marks around a genus name suggest that the species is likely misclassified.

Teloschistaceae is divided into three recognised subfamilies: Xanthorioideae, Caloplacoideae, and Teloschistoideae. In 2015, a proposed fourth subfamily, Brownlielloideae, emerged, but subsequent molecular research disputed its validity. A subsequent review revealed it to be more accurately described within subfamily Teloschistoideae, identifying it as an "artifactual taxon" with "chimeric" data origins. A deeper analysis of DNA sequences associated with genuine Teloschistaceae indicated members of Brownlielloideae scattered across the three acknowledged subfamilies, primarily in Teloschistoideae. A similar critique applies to Ikaerioideae, a subfamily that was informally introduced (but not validly published) by Sergey Kondratyuk and colleagues in 2020. Although evidence undermines the phylogenetic legitimacy of these two subfamilies, Kondratyuk's group persists in recognizing them, attributing nine genera to Brownlielloideae and two to Ikaerioideae. Each of the three accepted subfamilies includes crustose, foliose, and fruticose forms, indicating frequent evolutionary transitions between these forms. These subfamilies represent distinct clades in the phylogenetic tree of the Teloschistaceae, characterised by variations in the nucleic acid sequence patterns of their nuclear large ribosomal subunit.

• Caloplacoideae Arup, Søchting & Frödén (2020)

Type genus: Caloplaca. This subfamily was proposed by Ester Gaya and colleagues in 2012, used by Ulf Arup and colleagues in their 2013 publication, and finally published validly in 2020. Caloplacoideae contains mostly crustose species, and collectively has a wide distribution and a diverse secondary chemistry.

• Teloschistoideae Arup, Søchting & Frödén (2020)

Type genus: Teloschistes. This subfamily was first informally proposed (without a valid diagnosis) in 2013, published the same year with a diagnosis but invalidly (without a unique identifier), and finally validly published in 2020. The subfamily has a largely Southern Hemisphere distribution.

• Xanthorioideae Arup, Søchting & Frödén (2020)

Type genus: Xanthoria. The name for this subfamily was originally proposed by Gaya and colleagues in 2012, and used by Arup and colleagues in 2013. The subfamily name was formally validated when it was published in 2020 with a diagnosis. Most Xanthorioideae species are found in the Northern Hemisphere.

The order Teloschistales was first proposed by David Hawksworth and Eriksson in 1986, with a single family (Teloschistaceae); other families were added later. In the 1990s, several authors recognised the Teloschistales as a suborder within the Lecanorales; as a suborder it was named Teloschistineae. Following the appearance of preliminary molecular studies, the Teloschistaceae was classified by some within the order Lecanorales, although others maintained the Teloschistales as a valid order. The large-scale, multigene phylogenetic study of the class Lecanoromycetes by Jolanta Miądlikowska and colleagues published in 2014 corroborated the ordinal status of the Teloschistales, and showed it comprises two clades: Letrouitineae (containing Brigantiaeaceae and Letrouitiaceae) and its sister clade, Teloschistineae (containing Teloschistaceae and Megalosporaceae). The suborder Teloschistineae was formally proposed by Ester Gaya and François Lutzoni in 2015.

Molecular phylogenetics

The widespread application of molecular techniques to the Teloschistaceae has illuminated the variability of many morphological and anatomical characters, demonstrating their unreliability as evolutionary markers. With the advancements in molecular techniques, differentiation of species once considered phenotypically indistinguishable became clearer, as evidenced by the semi-cryptic species group containing the closely named Caloplaca micromarina, C. micromontana, and C. microstepposa.

Despite the Teloschistaceae's prominence in GenBank with over 6400 DNA sequence, early molecular studies often faced limitations due to insufficient sampling of representative species. A significant step forward was the multi-gene analysis by Ester Gaya and colleagues in 2012, marking one of the initial comprehensive phylogenetic evaluations of the Teloschistales.

Historically, genera within Teloschistaceae were distinguished based on attributes like growth form, cortical layer nature, rhizine presence, or spore type. Molecular insights have since shows that many of these taxonomic distinctions such as those between Caloplaca and Xanthoria, were problematic. Gaya's 2012 study emphasized the need for a molecular phylogenetic approach to understand Teloschistaceae's true taxonomy, especially given the reliance on previously unreliable characters for classification. This sentiment was echoed by Sergey Kondratyuk and his team, who emphasized the importance of using monophyletic groups for classifying genera within the Teloschistaceae, highlighting a departure from the old morphology-based classifications.

The revelation that the family's most extensive genus, Caloplaca, is polyphyletic led to proposals for multiple smaller genera to more accurately reflect the family's phylogenetic relationships. Although scientifically driven, these proposed taxonomic shifts met resistance, especially in regions like Australia. Given the myriad taxonomic changes the Teloschistaceae has undergone, scholars like Robert Lücking advocate for a comprehensive multi-locus analysis using all available data.

In 2018, a study by Kraichak and colleagues elucidated the broader phylogenetic relationships of the Teloschistaceae within the Lecanoromycetes, revealing the family's sister taxon relationship with Megalosporaceae.

Description

In general, Teloschistaceae members are known for their vibrant colours, spanning a spectrum of yellow, orange, and red hues, attributed to anthraquinone pigments. This group of lichens demonstrates a broad range of physical forms — from the thin, encrusting (crustose) to leaf-like (foliose), or even bushy (fruticose) formations. Although it is an atypical growth form for the Teloschistaceae, members of genus Ioplaca are somewhat umbilicate, meaning they have a somewhat circular, leafy thallus attached to the substrate at a single point.

Teloschistaceae lichens have a symbiotic relationship with a photobiont, generally a member of the green algal genus Trebouxia. Their reproductive structures, or ascomata, are usually brightly coloured. In most species, apotheciate ascomata have a lecanorine form, in which the apothecial disc is surrounded by a pale rim of tissue known as a thalline margin. Fewer Teloschistaceae species have biatorine or lecideine forms, in which the apothecial disc lacks a thalline margin. Reproductive propagules, such as isidia and soredia, can be found in select species.

The ascomata encase asci, cylindrical formations that commonly contain between four to sixteen ascospores, with eight being the most prevalent count. These asci are characterised by a well-developed J+ layer amyloid cap and a rudimentary internal apical apparatus. (The term "J+" refers to the positive reaction of the ascus tip to iodine, specifically when it turns blue or dark blue in the presence of iodine-based solutions like Melzer's reagent or Lugol's solution.) The translucent (hyaline) ascospores typically feature between one and three internal partitions called septa, marked by a robust central septum and a canal connecting the internal cavities, or lumina. Despite the polarilocular nature of ascospores suggesting Teloschistaceae lineage, these spores are often not overtly distinctive. Although polarilocular ascospores were formerly considered to be a distinguishing feature of the Teloschistaceae, the addition of genera like Apatoplaca, Cephalophysis, Fulgensia, and Xanthopeltis, all of which have simple or septate spores, prompted a reevaluation of the primary characteristics defining this family.

A distinctive feature of Teloschistaceae is the presence of the gelatinous paraphyses, with either unbranched or slightly branched structures culminating in bulbous ends. Within this family, asexual reproduction leads to the creation of pycnidia-type conidiomata, producing clear conidia that can be either bacillar (rod-shaped) or bifusiform (double-spindle shaped). The tissue composition of the thallus and apothecia is characterised by a loosely paraplectenchymatous structure, wherein the constituent fungal hyphae are oriented in various directions.

Morphological variety of Teloschistaceae

crustose, leprose: Leproplaca chrysodeta fruticulose: Polycauliona coralloides crustose, placodioid: Variospora aurantia lichenicolous lichen Erichansenia epithallina (red) growing on the crustose Rhizoplaca novomexicana fruticose: Xanthomendoza oregana foliose: Xanthoria parietina squamulose: Squamulea squamosa

Photobionts

In lichens, photobionts are the photosynthetic organisms that collaborate with fungal partners to enable the unique lichen symbiosis. Members of the Teloschistaceae primarily associate with trebouxioid green algal photobionts. An early study investigating the ultrastructure of the interaction between the fungus and alga in various Teloschistaceae species revealed that, in most cases, the cells were merely in close proximity to one another, with only a few instances of fungal cells invading the algal cells. The widespread Xanthoria parietina species complex has been identified to be in association with various Trebouxia species, including T. arboricola, T. decolorans, and T. italiana. Within the order Teloschistales, unlike the Teloschistaceae, species in the families Letrouitiaceae and Megalosporaceae primarily partner with the green algal genus Dictyochloropsis. Due to their resilience to desiccation, Trebouxia species serve as the main photobionts for lichen-forming fungi found in extreme environments such as the Antarctic, Arctic, alpine regions, and deserts, where lichens face continual exposure to intense dryness and temperature shifts.

Research on Teloschistaceae photobionts has shown that all studied foliose (Xanthoria, Xanthomendoza) and fruticose (Teloschistes) types were affiliated with specificTrebouxia clades. This indicates a degree of specificity at the genus level, where only certain subclades of the Trebouxia clade are seen as suitable partners. This specificity, however, can vary based on the habitat; in extreme climates, lichens might be associated with a broader range of photobionts.

Chemistry

Parietin (top) and the structurally similar emodin (bottom) are anthraquinone pigments common in the Teloschistaceae.

The main group of lichen products associated with the Teloschistaceae are chemical pigments called anthraquinones. These substances, which are deposited in the upper cortical layer of the lichen, have photoprotective properties, as they can absorb ultraviolet (UV) and blue light. Evolutionary innovations in secondary metabolite production allowed the family to broaden its range and transition from shaded, plant-based habitats to sun-exposed, arid environments. The production of protective chemicals is thought to be a direct contributor to the evolutionary success of the familial lineage. A 2023 study reported using comparative genomics to identify a metabolic gene cluster involved in anthraquinone metabolism and shared uniquely across the Teloschistales. Phylogenetic analyses of fungal polyketide synthases (PKSs) reveal a consistent grouping, hinting at a shared ancestral trait for anthraquinone biosynthesis within the subphylum Pezizomycotina. While the genetic machinery (like the PKSs) involved in anthraquinone biosynthesis in Teloschistales and some non-lichenized fungi is conserved and exhibits similarities, the specific arrangement of the involved enzymes seems to be a distinguishing feature in the Teloschistales' approach to anthraquinone biosynthesis. The discovery of an ABC transporter gene within the pigment gene cluster provides clues as to how the lichens are able to accumulate large amounts of potentially toxic anthraquinone crystals in their thallus and reproductive structures.

Several early chemical studies (published between the years 1897 and 1906) by Friedrich Wilhelm Zopf and Oswald Hesse involving Teloschistaceae members involved the isolation of the reddish pigment parietin from selected species. Parietin is an antioxidant molecule that is produced in greater amounts (upregulated) in lichen thalli that are exposed to excess nitrogen. In a 1970 publication, Johan Santesson surveyed 230 Caloplaca species for anthraquinones as part of a phytochemical study of the Teloschistaceae, and noted that the studied species could be arranged according to their anthraquinone content in thirteen "chemical groups". In 1997, Ulrik Søchting analysed secondary metabolites from species of Caloplaca, Teloschistes, and Xanthoria to look for chemical patterns of consistent combinations and proportions of lichen products. He identified two chemosyndromes with parietin, emodin, teloschistin, fallacinal, and parietinic acid as the main substances. Parietin acts as a UV-light filter to provide optimal light intensities for the photobionts that are resident in the internal algal layer. Investigations into the parietin concentration in Xanthoria parietina across a light gradient reveal a direct relationship between light intensity and concentration. In the Teloschistaceae, parietin may serve an additional defensive role. In the Negev desert, the parietin-containing Elenkiniana ehrenbergii and Seirophora lacunosa are avoided by snails, while they frequently consume species like Diploicia canescens and Buellia subalbula, which lack parietin.

In their large-scale phylogenetic analysis of the Teloschistaceae, Arup and colleagues analysed about 4000 members of the family using high-performance liquid chromatography, and identified more than 100 secondary metabolites (lichen products), mostly anthraquinones. They noted that in the large majority of cases, the distribution of lichen products was more or less constant within species. In some instances, the secondary chemistry is important at higher taxonomic levels (i.e., a rank higher than species). For example, the genus Catenaria, which contains three South American species, is characterised by the presence of 7-chlorocatenarin, a secondary metabolite previously unknown in lichens. Similarly, the substance usnic acid characterises the genus Usnochroma, while 5-chloroemodin occurs in all but one species of Shackletonia. The secondary chemistry of the Caloplacoideae is the most diverse amongst the three Teloschistaceae subfamilies, as it contains both chlorinated anthraquinones and depsidones.

Apothecia of Ikaeria serusiauxii grown in full light develop completely black margins resulting from the accumulation of the pigment Cinereorufa-green.

Although most Teloschistaceae lichen produce yellow-orange-red anthraquinone pigments, Apatoplaca and Cephalophysis are two Teloschistaceae genera that lack anthraquinones. Similarly, the genus Pyrenodesmia encompasses species where anthraquinones are absent and replaced by substances such as Cinereorufa‐green or Sedifolia-grey; these insoluble lichen pigments may confer UV-protective ability similar to anthraquinones. Taxa of the closely related genera Kuettlingeria and Sanguineodiscus have anthraquinones in their apothecia and Sedifolia-grey in their thalli. The species Kuettlingeria neotaurica features apothecia of two colour variants: orange-red (with anthraquinones) and grey (with Sedifolia-grey). The absence of anthraquinones is not a synapomorphic character, but appears independently in unrelated lineages of Teloschistaceae; as such, it is a phylogenetically unreliable character.

Adaptive radiation

Adaptive radiation in the Teloschistaceae has been studied to understand the key phenotypic changes leading to their diversification. This diversification is believed to be connected to the spread of anthraquinone pigments in their thallus. Initially, these pigments were thought to have appeared during the Teloschistaceae's first divergence, with a more widespread occurrence developing later. The distribution of anthraquinones varies, from being dispersed across the organism's surface to localized regions. Analysis suggests that the family's lineage witnessed a loss and subsequent return of these pigments over time, considering their presence in the thallus and apothecia as the ancestral state. Ecologically, these organisms shifted from shaded, bark-dwelling habitats to sunlit, rocky areas during their diversification.

Examining the relationship between phenotypic traits and diversification rates, it becomes evident that the presence of anthraquinones in the thallus and increased sun exposure accelerated diversification. On the contrary, living in shaded environments or having a crustose-continuous (smooth, non-scaly) growth form hindered diversification. The choice of substrate, be it rock or bark, did not have a pronounced impact on diversification rates. This adaptive radiation within the Teloschistaceae is estimated to have initiated around 100 million years ago, specifically during the Late Cretaceous period. Factors like climatic shifts, continental separations, and the emergence of flowering plants are theorised to have influenced the adaptive landscape. Such factors might have promoted the development of light-protective anthraquinones, enabling Teloschistaceae to colonize exposed environments. A notable aspect of their evolution is the diversification of anthraquinone genes, which is mainly attributed to gene modifications through gene reshuffling, leading to new biosynthetic enzyme pathways and gene clusters.

Genera

This section presents a compilation of the genera within the Teloschistaceae, based largely on a 2021 fungal classification review. Each genus is paired with its taxonomic authority, denoting the first describers using standardized author abbreviations, the publication year, and the respective number of species.

Contemporary estimates of the number of Teloschistaceae taxa include: 10 genera and 47 species (2001), 12 genera and 644 species (2008); 51–53 genera and about 700 species (2016); 65 genera and 755 species (2017); and 71 genera and about 840 species (2022). Also in 2022, Kondratyuk and colleagues enumerated all members of the Teloschistaceae with available DNA sequences, and confirmed 590 species in 115 genera. As of August 2023, Species Fungorum (in the Catalogue of Life), accepts 117 genera and 805 species in the Teloschistaceae. The largest genus is Caloplaca, at 173 accepted species.

In terms of diversity, Teloschistaceae stood as the sixth-largest lichen-forming fungal family by 2017, following the Parmeliaceae, Graphidaceae, Verrucariaceae, Ramalinaceae, and the Lecanoraceae. Genera are organised here by subfamily:

Caloplacoideae

Examples from subfamily Caloplacoideae (clockwise from upper left): Blastenia ferruginea; Caloplaca maculata; Igneoplaca ignea; and Kuettlingeria erythrocarpa

• Apatoplaca Poelt & Hafellner (1980) – 1 sp.
• Blastenia A.Massal. (1852) – 11 spp.
• Bryoplaca Søchting, Frödén & Arup (2013) – 3 spp.
• Caloplaca Th.Fr. (1860) – 351 spp.
• Cephalophysis (Hertel) H.Kilias (1985) – 1 sp.
• Eilifdahlia S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 2 spp.
• Elenkiniana S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 3 spp.
• Fauriea S.Y.Kondr., Lőkös & Hur (2016) – 7 spp.
• Franwilsia S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 3 spp.
• Fulgensia A.Massal. & De Not. (1853) – 2 spp.
• Gintarasiella S.Y.Kondr. & Hur (2017) – 1 sp.
• Gyalolechia A.Massal. (1852) – 40 spp.
• Hanstrassia S.Y.Kondr. (2017) – 2 spp.
• Huneckia S.Y.Kondr., Elix, Kärnefelt, A.Thell & Hur (2014) – 4 spp.
• Ioplaca Poelt (1977) – 2 spp.
• Jasonhuria S.Y.Kondr., Lőkös & S.O.Oh (2015) – 1 sp.
• Klauderuiella S.Y.Kondr. & Hur (2017) – 3 spp.
• Kuettlingeria Trevis. (1857) – 15 spp.
• Lacrima Bungartz, Arup & Søchting (2020) – 4 spp.
• Laundonia S.Y.Kondr., Lőkös & Hur (2017) – 2 spp.
• Lendemeriella S.Y.Kondr. (2020) – 9 spp.
• Leproplaca (Nyl.) Nyl. (1888) – 7 spp.
• Loekoesia S.Y.Kondr., S.O.Oh & Hur (2015) – 1 sp.
• Marchantiana S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 7 spp.
• Mikhtomia S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 4 spp.
• Obscuroplaca Søchting, Arup & Bungartz (2021) – 3 spp.
• Oceanoplaca Arup, Søchting & Bungartz (2020) – 6 spp.
• Olegblumia S.Y.Kondr., Lőkös & Hur (2020) – 1 sp.
• Opeltia S.Y.Kondr. & Lőkös (2017) – 4 spp.
• Oxneriopsis S.Y.Kondr., Upreti & Hur (2017) – 4 spp.
• Pisutiella S.Y.Kondr., Lőkös & Farkas (2020) – 6 spp.
• Pyrenodesmia A.Massal. (1852) – 6 spp.
• Rufoplaca Arup, Søchting & Frödén (2013) – 10 spp.
• Sanguineodiscus I.V.Frolov & Vondrák (2020) – 4 spp.
• Seirophora Poelt (1983) – 8 spp.
• Sucioplaca Bungartz, Søchting & Arup (2020) – 1 sp.
• Upretia S.Y.Kondr., A.Thell & Hur (2017) – 2 spp.
• Usnochroma Søchting, Arup & Frödén (2013) – 2 spp.
• Variospora Arup, Søchting & Frödén (2013) – 16 spp.
• Xanthaptychia S.Y.Kondr. & Ravera (2017) – 3 spp.
• Yoshimuria S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 4 spp.

Teloschistoideae

Examples from subfamily Teloschistoideae (clockwise from upper left): Brownliella cinnabarina; Niorma hosseusiana; Wetmoreana brouardii; and Fulgogasparrea appressa

• Aridoplaca Wilk, Pabijan & Lücking (2021) – 1 sp.
• Brownliella S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2013) – 4 spp.
• Catenarina Søchting, Søgaard, Arup, Elvebakk & Elix (2014) – 3 spp.
• Cinnabaria Wilk, Pabijan & Lücking (2021) – 1 sp.
• Elixjohnia S.Y.Kondr. & Hur (2017) – 4 spp.
• Filsoniana S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2013) – 9 spp.
• Follmannia C.W.Dodge (1967) – 2 spp.
• Fulgogasparrea S.Y.Kondr., M.H.Jeong, Kärnefelt, Elix, A.Thell & Hur (2013) – 5 spp.
• Haloplaca Arup, Søchting & Frödén (2013) – 3 spp.
• Harusavskia S.Y.Kondr. (2017) – 1 sp.
• Hosseusiella S.Y.Kondr., L.Lőkös, Kärnefelt & A.Thell (2018) – 3 spp.
• Ikaeria S.Y.Kondr., D.Upreti & Hur (2017) – 2 spp.
• Iqbalia Fayyaz, Afshan & S.Y.Kondr. (2022) – 1 sp.
• Josefpoeltia S.Y.Kondr. & Kärnefelt (1997) – 3 spp.
• Kaernefia S.Y.Kondr., Elix, A.Thell & Hur (2013) – 3 spp.
• Lazarenkoiopsis S.Y.Kondr., Lőkös & Hur (2017) – 1 sp.
• Loekoeslaszloa S.Y.Kondr., Kärnefelt, A.Thell & Hur (2019) – 2 spp.
• Neobrownliella S.Y.Kondr., Elix, Kärnefelt & A.Thell (2015) – 5 spp.
• Nevilleiella S.Y.Kondr. & Hur (2017) – 2 spp.
• Niorma A.Massal. (1861) – 5 spp.
• Raesaeneniana S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) – 1 sp.
• Rehmanniella S.Y.Kondr. & Hur (2018) – 5 spp.
• Scutaria Søchting, Arup & Frödén (2013) – 1 sp.
• Sirenophila Søchting, Arup & Frödén (2013) – 4 spp.
• Stellarangia Frödén, Arup & Søchting (2013) – 3 spp.
• Streimanniella S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) – 4 spp.
• Tarasginia S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) – 2 spp.
• Tassiloa S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) – 2 spp.
• Tayloriellina S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2016) – 2 spp.
• Teloschistes Norman (1852) – ca. 24 spp.
• Teloschistopsis Frödén, Søchting & Arup (2013) – 3 spp.
• Thelliana S.Y.Kondr., Kärnefelt, Elix & Hur (2015) – 1 sp.
• Villophora Søchting, Arup & Frödén (2013) – 9 spp.
• Wetmoreana Arup, Søchting & Frödén (2013) – 2 spp.
• Wilketalia S.Y.Kondr (2021) – 1 sp.

Xanthorioideae

Examples from subfamily Xanthorioideae (clockwise from upper left): Athallia holocarpa; Calogaya saxicola; Dufourea ligulata; and Xanthocarpia crenulatella

• Amundsenia Søchting, Garrido-Ben., Arup & Frödén (2014) – 2 spp.
• Athallia Arup, Frödén & Søchting (2013) – 17 spp.
• Austroplaca Søchting, Frödén & Arup (2013) – 10 spp.
• Calogaya Arup, Frödén & Søchting (2013) – 19 spp.
• Cerothallia Arup, Frödén & Søchting (2013) – 4 spp.
• Charcotiana Søchting, Garrido-Ben. & Arup (2014) – 1 sp.
• Coppinsiella S.Y.Kondr. & Lőkös (2018) – 3 spp.
• Dijigiella S.Y.Kondr. & L.Lőkös (2017) – 2 spp.
• Dufourea Ach. (1809) – 25 spp.
• Erichansenia S.Y.Kondr., Kärnefelt & A.Thell (2020) – 3 spp.
• Flavoplaca Arup, Søchting & Frödén (2013) – 28 spp.
• Fominiella S.Y.Kondr., Upreti & Hur (2017) – 2 spp.
• Gallowayella S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix & A.Thell (2012) – 15 spp.
• Golubkovia S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 1 sp.
• Gondwania Søchting, Frödén & Arup (2013) – 4 spp.
• Honeggeria S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix, Hur & A.Thell (2012) – 1 sp.
• Huriella S.Y.Kondr. (2017) – 5 spp.
• Igneoplaca S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 1 sp.
• Jackelixia S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt & A.Thell (2009)
• Jesmurraya S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix, Hur & A.Thell (2012) – 1 sp.
• Kudratoviella S.Y.Kondr., L.Lőkös, Kärnefelt & A.Thell (2022) – 5 spp.
• Langeottia S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 2 spp.
• Lazarenkoella S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) – 2 spp.
• Martinjahnsia S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix, Hur & A.Thell (2012) – 1 sp.
• Massjukiella S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix, Hur & A.Thell (2012) – 8 spp.
• Orientophila Arup, Søchting & Frödén (2013) – 15 spp.
• Ovealmbornia S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix & A.Thell (2009) – 3 spp.
• Oxneria S.Y.Kondr. & Kärnefelt (2003) – 4 spp.
• Pachypeltis Søchting, Arup & Frödén (2013) – 7 spp.
• Parvoplaca Arup, Søchting & Frödén (2013) – 6 spp.
• Pisutiella S.Y.Kondr., Lőkös & Farkas (2020) – 5 spp.
• Polycauliona Hue (1908) – 18 spp.
• Rusavskia S.Y.Kondr. & Kärnefelt (2003) – 19 spp.
• Scythioria S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 3 spp.
• Seawardiella S.Y.Kondr., I.Kärnefelt & A.Thell (2018) – 2 spp.
• Shackletonia Søchting, Frödén & Arup (2013) – 5 spp.
• Solitaria Arup, Søchting & Frödén (2013) – 1 sp.
• Squamulea Arup, Søchting & Frödén (2013) – 15 spp.
• Teuvoahtiana S.Y.Kondr. & Hur (2017) – 3 spp.
• Tomnashia S.Y.Kondr. & Hur (2017) – 4 spp.
• Verrucoplaca S.Y.Kondr., Kärnefelt, Elix, A.Thell & Hur (2014) – 1 sp.
• Xanthocarpia A.Massal. & De Not. (1853) – 12 spp.
• Xanthodactylon P.A.Duvign. (1941) – 2 spp.
• Xanthokarrooa S.Y.Kondr., Fedorenko, S.Stenroos, Kärnefelt, Elix & A.Thell (2009) – 2 spp.
• Xanthomendoza S.Y.Kondr. & Kärnefelt (1997) – 20 spp.
• Xanthopeltis R.Sant. (1949) – 1 sp.
• Xanthoria (Fr.) Th.Fr. (1860) – 10 spp.
• Zeroviella S.Y.Kondr. & Hur (2015) – 8 spp.

Some of the genera proposed during the recent restructuring of the family have since been shown to be nomenclaturally illegitimate or unavailable for use. For example,

• Andina Wilk, Pabijan & Lücking (2021) has been replaced with Wilketalia.
• Phaeoplaca Søchting, Arup & Bungartz (2020) has been replaced with Obscuroplaca.
• Tayloriella S.Y.Kondr., Kärnefelt, A.Thell, Elix & Hur (2015) has been replaced with Tayloriellina.

Habitat, distribution, and ecology

The scrambled egg lichen, Gyalolechia fulgens, is a terricolous species and a component of some biological soil crusts.

This rock in Gaspereau Lake is frequented by great black-backed gulls, creating the conditions for a localised nitrogen-rich environment conducive to the growth of the orange lichen Rusavskia elegans.

Collectively, the family has a cosmopolitan distribution, although members occur predominantly in subtropical and temperate regions. Most members either grow on rock (saxicolous) or on bark (corticolous). As an exception to this general ecological preference, genus Bryoplaca contains species that only grow on mosses and detritus. Some Fulgensia species grow on soils (terricolous), particularly those rich in lime. Several crustose Teloschistaceae species, typically saxicolous in nature, have been recorded growing on human bone remains recovered at a looted Late Holocene aboriginal cairn burial site in South America.

In general, the family is moderately to strongly nitrophilous. This suggests a preference of many of its species for habitats that are rich in nitrogen, particularly in the form of nitrate. Sun-adapted lichens, such as the Teloschistaceae, have an enhanced ability to upregulate the levels at which they fix carbon from the atmosphere and absorb excess nitrogen. Small foliose and crustose lichens are in general more tolerant to higher levels of nitrogen. Xanthoria parietina is one example of a widespread lichen that appears to be experiencing an increase in its range due to its ability to tolerate nitrogenous pollutants, and its potential ability to displace native lichen species as a result. Caloplaca, Fulgensia, Teloschistes, and Xanthoria are genera that are characteristic of sun-exposed habitats; in some extreme desert environments, Caloplaca (in the broad sense) may be the only genus present, while Caloplaca and Xanthoria dominate harsh coastal environments.

There are several Teloschistaceae genera that contain lichenicolous (lichen-dwelling) species. These originate from subfamily Caloplacoideae: Caloplaca (26 spp.), Gyalolechia (1 sp.), Variospora (1 sp.); from subfamily Teloschistoideae: Catenarina (1 sp.), Sirenophila 1; and from subfamily Xanthorioideae: Flavoplaca (4 spp.), Pachypeltis (1 sp.), and Shackletonia (3 spp.). Lichenicolous species within the Teloschistaceae generally have a broad range of hosts. Their geographical distribution seems to be influenced not just by the classification of their host lichen, but also by the substrate they grow on.

Teloschistaceae has a high diversity in polar regions and a substantial number of bipolar species, i.e., species occurring in both northern and southern hemispheres but largely absent from intermediate, tropical latitudes. Examples include Xanthomendoza borealis, Austroplaca soropelta, and Caloplaca phlogina. Conversely, there is a relatively low diversity of crustose Teloschistaceae in Central Europe. Localised exceptions occur in primarily in sunlit locations with either calcareous or nutrient-rich siliceous rock formations; these habitats are predominant in the alpine regions of the Alps and the Carpathian Mountains, as well as in the arid, warm rocky steppes. Some Teloschistaceae genera have a strong geographic centre of species richness; examples include Elixjohnia (Australasia), Orientophila (east Asia), Shackletonia (Antarctic and subantarctic), Stellarangia (south-western Africa) and Xanthoria (Mediterranean area).

Several studies published in the previous decade have enumerated the Teloschistaceae taxa occurring in certain defined geographical areas. These include:

• Altai-Sayan region, 103 species in 31 genera
• Crimea, 119 species
• Dagestan, 85 species
• India, 115 species in 36 genera
• Italy, about 160 species
• Galápagos Islands, 24 species
• Mexico, 142 species in 6 genera
• New Zealand, about 100 species
• Russian Far East, 84 species
• Ural, 81 species

Species interactions

Many lichenicolous fungi infect Teloschistaceae members, typically showing specificity to a particular species or genus within the family. However, Cercidospora caudata and Stigmidium cerinae stand out for their broader host range within Teloschistaceae. The fungus Tremella caloplacae demonstrates a notable interaction with Teloschistaceae lichens. Comprehensive research, fusing molecular and ecological insights, has unveiled at least six unique lineages of Tremella caloplacae that are host-specific, hinting at a potential species complex. This fungus's diversification mirrors the swift emergence of Teloschistaceae since the late Cretaceous, suggesting that new fungal species evolved alongside the adaptive radiation of these lichens.

Human interactions and uses

Economic significance

The crustose Igneoplaca ignea covers walls of the Fortaleza de Santa Teresa, a 260-year-old military fortification in Uruguay.

There are no species in the Teloschistaceae that have any major economic significance. The ability of some members to grow on rock surfaces, however, has led to several recorded instances where Teloschistaceae species have damaged marble surfaces. In some cases, the lichens, the major contributor of which was Xanthocarpia feracissima, penetrated up to 10 mm (3⁄8 in) into the stone along larger cracks and 0.05 mm (1⁄500 in) beneath loose surface crystals, leading to crumbling of the marble surface. Caloplaca pseudopoliotera and C. cupulifera are two crustose species implicated in the slow degradation of the Konark Sun Temple in India.

Traditional medicine

Several Teloschistaceae species have been used in traditional medicines. Polycauliona candelaria was used in Europe (early modern era) where it was boiled with milk to treat jaundice, along with Xanthoria parietina. Rusavskia elegans was used in Afghanistan, where it was ground and applied to infected wounds for humans and livestock (Wakhan region). In Kyrgyzstan, it was ground and applied to wounds on livestock; or ground, mixed in butter, and fed to livestock (especially yak calves) with diarrhea. Teloschistes flavicans is used in China to "clear heat in the lung and liver", and to remove toxins. Xanthomendoza fallax is used in Traditional Tibetan medicine.

The common and widespread species Xanthoria parietina has a long history of traditional use. It has been recorded for several uses in various regions of Spain, including: as a decoction in wine for menstrual complaints; as a decoction in water for kidney disorders; as a decoction in water for toothaches; as an analgesic for several pains; and as an ingredient in a cough syrup. In early modern era Europe, it was boiled with milk to treat jaundice (along with Polycauliona candelaria), used for diarrhea and dysentery, to stop bleeding, as a quinine replacement for malaria, and for hepatitis. In Traditional Chinese medicine the lichen has been used as an antibacterial.

In science

Xanthoria parietina has been suggested for use as a potential reliable pollutant tolerance biomonitor in urban ecosystems due to its widespread presence and ability to adapt to high pollution levels. Rusavskia elegans has been studied in experiments where specimens were exposed to outer space conditions, including extreme temperatures, ultraviolet radiation, and ultra-high vacuum. The results showed the lichen to have an impressive ability to survive under these conditions.

Conservation

Caloplaca allanii is a poorly known New Zealand endemic.

The conservation status of three Teloschistaceae species have been assessed for the global IUCN Red List. Caloplaca rinodinae-albae (vulnerable, 2017) is at risk from tourism development and increased erosion on Sardinia's coasts. Seirophora aurantiaca (endangered, 2020) is particularly vulnerable to climate change impacts in the Canadian Arctic, leading to eroding coasts, increased sea ice melt, saline wash from storm surges, permafrost melting, and potential invasive species intrusions. Teloschistes peruensis (critically endangered, 2021) is at risk due to multiple threats in Peru, including potential development, habitat fragmentation, 4x4 races like the Dakar Rally, air pollution, and the presence of invasive species like goats and cows altering the habitat. Other Teloschistaceae members, some with limited geographic distributions, make appearances on regional lists. For example, the crustose New Zealand endemic Caloplaca allanii, first documented in 1932, was not collected again until 81 years later; because of its sparsity and small total area of occupancy, it has been assessed as "Threatened/Nationally Critical" using the New Zealand Threat Classification System.

In some large geographical areas, the full extent of the diversity of Teloschistaceae taxa is not well known. Examples include South America, where the family has not historically received much attention, and China, where of 2,164 lichen species evaluated for inclusion on its red list, only 49 were members of the Teloschistaceae; 13 of those were listed as least-concern species, and the other 36 as data deficient.

Citations

Cited literature

• Arup, Ulf; Søchting, Ulrik; Frödén, Patrik (2013). "A new taxonomy of the family Teloschistaceae". Nordic Journal of Botany. 31 (1): 16–83. doi:10.1111/j.1756-1051.2013.00062.x.
• Bungartz, Frank; Søchting, Ulrik; Arup, Ulf (2020). "Teloschistaceae (lichenized Ascomycota) from the Galapagos Islands: a phylogenetic revision based on morphological, anatomical, chemical, and molecular data". Plant and Fungal Systematics. 65 (2): 515–576. doi:10.35535/pfsyst-2020-0030. S2CID 234385561.
• Kondratyuk, S.; Jeong, M.-H.; Yu, N.-H.; Kärnefelt, I.; Thell, A.; Elix, J.; Kim, J.; Kondratyuk, A.; Hur, J.-S. (2013). "Four new genera of teloschistoid lichens (Teloschistaceae, Ascomycota) based on molecular phylogeny". Acta Botanica Hungarica. 55 (3–4): 251–274. doi:10.1556/abot.55.2013.3-4.8.
• Kondratyuk, S.Y.; Kärnefelt, I.; Thell, A.; Elix, J.A.; Kim, J.; Kondratiuk, A.S.; Hur, J.-S. (2015b). "Brownlielloideae, a new subfamily in the Teloschistaceae (Lecanoromycetes, Ascomycota)" (PDF). Acta Botanica Hungarica. 57 (3–4): 321–343. doi:10.1556/034.57.2015.3-4.6.
• Kondratyuk, S.Y.; Lőkös, L.; Upreti, D.K.; Nayaka, S.; Mishra, G.K.; Ravera, S.; Jeong, M.-H.; Jang, S.-H.; Park, J.S.; Hur, J.S. (2017). "New monophyletic branches of the Teloschistaceae (lichen-forming Ascomycota) proved by three gene phylogeny". Acta Botanica Hungarica. 59 (1–2): 71–136. doi:10.1556/034.59.2017.1-2.6. hdl:10447/414429.
• Wilk, Karina; Pabijan, Maciej; Saługa, Marta; Gaya, Ester; Lücking, Robert (2021). "Phylogenetic revision of South American Teloschistaceae (lichenized Ascomycota, Teloschistales) reveals three new genera and species". Mycologia. 113 (2): 278–299. doi:10.1080/00275514.2020.1830672. PMID 33428561. S2CID 231586897.