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 Roccellaceae are a family of mostly lichen-forming fungi in the order Arthoniales, circumscribed by the French botanist François Fulgis Chevallier in 1826. Species in the family exhibit various growth forms, including crustose and fruticose thalli, and diverse reproductive structures. Roccellaceae species typically have apotheciate or lirellate ascomata, often with distinct blackened margins. Molecular phylogenetics studies have revealed significant genetic diversity and complex evolutionary histories within the family.
Feigeana is a genus of lichenized fungi in the family Roccellaceae. A monotypic genus, it contains the single species Feigeana socotrana, first reported from Yemen in 1995.
Enterographa is a genus of lichens in the family Roccellaceae.
Dirina is a genus of lichen-forming fungi in the family Roccellaceae. All Dirina species are crustose lichens with a whitish to greyish brown thallus, and live either on rock or on bark–some species can live on both. The photobiont partner is a member of the green algal genus Trentepohlia. Most species occur in the Northern Hemisphere, and are generally restricted to coastal habitats, where they may be locally quite common. Erythrin and lecanoric acid are lichen products that usually occur in Dirina species, along with several other unidentified substances.
Lecanographa is a genus of about 40 species of lichens in the family Lecanographaceae. It was circumscribed in 1994 by José M. Egea and Pilar Torrente, with Lecanographa lyncea as the type species.
Lecanactis is a genus of crustose lichens, commonly called old wood rimmed lichen. The genus was circumscribed in 1855 by German lichenologist Gustav Wilhelm Körber, who assigned Lecanactis abietina as the type species.
Simonyella is a genus of lichenized fungi in the family Roccellaceae. A monotypic genus, it contains the single species Simonyella variegataJ. Steiner (1902).
Streimannia is a genus of lichenized fungi in the family Roccellaceae. A monotypic genus, it contains the single species Streimannia varieseptata. The genus was circumscribed by Göran Thor in Opera Bot. vol.103 on page 84 in 1990.
Heufleria is a genus of fungi in the Rhytismatales order.
Opegraphaceae is a family of lichen-forming and lichenicolous fungi in the order Arthoniales. It was originally proposed by German lichenologist Ernst Stizenberger in 1862. It fell into disuse, but was resurrected in a molecular phylogenetic study of the order Arthoniales published in 2010. It now includes taxa that were previously referred to the family Roccellaceae, its sister group.
Dictyographa is a genus of lichen-forming fungi in the family Opegraphaceae. It comprises three species of corticolous (bark-dwelling), crustose lichens. The genus was originally described by the Swiss scientist Johannes Müller Argoviensis in 1893, who distinguished it from related genera by its unique spore structure and interconnected filaments within its reproductive organs. Dictyographa lichens are characterised by their elongated, slit-like fruiting bodies and spores that are divided by both vertical and horizontal internal walls. The genus has been subject to taxonomic debate, with some researchers proposing to merge it with the related genus Opegrapha. However, genetic studies have since confirmed Dictyographa as a distinct evolutionary lineage. These lichens are found in various parts of the world, including Africa, the Middle East, and Hawaii, typically growing in coastal environments.
Austroroccella is a single-species genus in the family Roccellaceae. It contains Austroroccella gayana, a saxicolous (rock-dwelling), fruticose lichen. This lichen produces dark to black discs lacking pruina, and it contains roccellic acid as its only lichen product. The genus was circumscribed in 2013 by Anders Tehler, Martin Irestedt, and Damien Ertz based on molecular phylogenetic analysis that showed that the species belongs in an isolated clade in the Roccellaceae along with Dendrographa, Syncesia, and Roccellina.
Crocellina is a monotypic fungal genus in the family Roccellaceae. It contains the single species Crocellina cinerea, a saxicolous (rock-dwelling), crustose lichen that is endemic to Socotra Island in the Indian Ocean. This species was first described in 1882 by Swiss botanist Johannes Müller Argoviensis as Dirina cinerea, and later transferred to genus Roccellina in 1983. Crocellina was circumscribed in 2014 by Anders Tehler and Damien Ernst, following molecular phylogenetic analysis and revision of the Roccellaceae.
Psoronactis is a monotypic fungal genus in the family Roccellaceae. It contains the single species Psoronactis dilleniana, a saxicolous (rock-dwelling), crustose lichen. This species was first described in 1799 by Swedish lichenologist Erik Acharius as Lichen dillenianus. The taxon was shuffled to several genera in the 1800s as different authors had different opinions on how to classify the species; in more modern times, it was transferred to genus Lecanographa in 2013. Psoronactis was circumscribed in 2014 by Damien Ernst and Anders Tehler, following molecular phylogenetic analysis and revision of the Roccellaceae that showed the species occupied a distinct lineage in the family. The genus name alludes to the lichen products present in its thallus: psoromic acid and 2'-O-demethylpsoromic acid. It is these compounds that differentiate it chemically from the similar genus Lecanactis.
Diromma is a monotypic fungal genus in the family Roccellaceae. It contains the single species Diromma dirinellum, a rare crustose lichen that grows as a parasite on the lichen Dirina ceratoniae. It has a distribution restricted to the Mediterranean Basin.
Pseudoschismatomma is a monotypic fungal genus in the family Roccellaceae. It contains the single species Pseudoschismatomma rufescens, a corticolous (bark-dwelling), crustose lichen. This species was first described in 1794 by Christiaan Hendrik Persoon as Opegrapha rufescens. Pseudoschismatomma was circumscribed in 2014 by Damien Ernst and Anders Tehler, following molecular phylogenetic analysis and revision of the Roccellaceae. The genus name alludes to its similarity with genus Schismatomma, particularly S. graphidioides. It differs from this species in having a distinct brown true exciple.
Dirina approximata is a species of corticolous (bark-dwelling), crustose lichen in the family Roccellaceae. It was formally described by Alexander Zahlbruckner in 1931. It is endemic to the Galápagos Islands, where it grows on the bark of various trees and shrubs. Its sister species is Dirina sorocarpa, which is endemic to the Cape Verde Islands; Anders Tehler suggests that the large disjunct distribution between the two is the result of "ancient long distance dispersal event".
Dirina badia is a species of crustose lichen in the family Roccellaceae. It is found on the small desert mountains of northern Peru, where it grows on both stone and on bark.
Dirina candida is a species of saxicolous (rock-dwelling), crustose lichen in the family Roccellaceae. It is found in the southern Mediterranean Basin, with a range extending east to Egypt and Libya. It grows on calcareous rocks that are close to the sea. The lichen was formally described as a new species in 1885 by Johannes Müller Argoviensis from specimens collected in Alexandria, Egypt. Anders Teher and Damien Ertz transferred it to Dirina in 2013. Tehler had previously (1983) referred this species to Dirina immersa, but later molecular phylogenetic analysis revealed that it should instead be considered a distinct species, despite the two sharing the same appearance, morphology, and chemistry.
