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.
The Roccellaceae are a family of fungi in the order Arthoniomycetes. Most taxa are lichenized with green algae, although some are lichenicolous, growing on other lichens.
Chiodecton is a genus of lichens in the family Roccellaceae. The genus was circumscribed by lichenologist Erik Acharius in 1814, with Chiodecton sphaerale assigned as the type species.
Enterographa is a genus of lichens in the family Roccellaceae.
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.
Schizopelte is a genus of lichen-forming fungi in the family Opegraphaceae. The genus was circumscribed by Theodor Magnus Fries in 1875. It was resurrected for use in 2011 by Damien Ertz and Anders Tehler, who published a phylogenetic study of the order Arthoniales. In addition to the type species, S. californica, they included a former Hubbsia species, a former Llimonaea species, and a species new to science in the resurrected Schizopelte.
Syncesia is a genus of lichen-forming fungi in the family Roccellaceae.
Alyxoria is a genus of lichen-forming fungi in the family Lecanographaceae.
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.
Roccellographaceae is a family of lichen-forming fungi in the order Arthoniales. It contains three genera: Dimidiographa, Fulvophyton, and Roccellographa.
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.
Vigneronia is a genus of lichen-forming fungi in the family Roccellaceae. It has five species. The genus was circumscribed in 2014 by Damien Ernst, with Vigneronia spieri assigned as the type species. This species, originally described as Schismatomma spieri from collections made in the Galápagos Islands, has since been recorded from mainland Ecuador and the Antilles (Curaçao). The genus is named after Ernst's wife, Nathalie Vigneron, who accompanied him on collecting trips.
Gyrographa is a genus of lichen-forming fungi in the family Roccellaceae. The genus was circumscribed in 2014 by Damien Ernst and Anders Tehler, with Gyrographa gyrocarpa assigned as the type species. This lichen, originally described by Julius von Flotow in 1825, was first placed in the genus Opegrapha. Species in the genus have a crustose thallus lacking a cortex, and a dark brown prothallus. The photobiont partner is trentepholioid. The hypothecium is thick and carbonised, and the ascospores lack a gelatinous sheath; these characteristics distinguish it from Opegrapha species. The genus name alludes to the gyrose ascomata of the type species.
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.
Gyronactis is a genus of lichen-forming fungi in the family Roccellaceae. It has two species. The genus was circumscribed by Damien Ernst and Anders Tehler in 2014, with G. asiatica assigned as the type species. This lichen, formerly placed in Lecanactis, is only known from the type locality in Myanmar. The genus name alludes to both its similarity with Lecanactis and the presence of gyrophoric acid in the thallus.
Isalonactis is a monotypic fungal genus in the family Roccellaceae. It contains the single species Isalonactis madagascariensis, a saxicolous (rock-dwelling), crustose lichen found in Madagascar. Both the genus and species were described as new in 2014 by Damien Ertz, Anders Tehler, Eberhard Fischer, Dorothee Killmann, Tahina Razafindrahaja, and Emmanuël Sérusiaux. The type was collected on the Isalo Massif at an altitude of 851 m (2,792 ft); there, it was found growing on sheltered mesozoic sandstone cliffs. The genus name alludes to both Isalo Massif, the type locality, and the phylogenetic relatedness to genus Lecanactis.
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.
