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.
Cryptothecia is a genus of white to greenish crustose lichens that grow on bark, wood, or leaves, in tropical or subtropical areas worldwide. It has a conspicuous prothallus that develops around its periphery which can be bright red in some species, hence the common name wreath lichen. The main vegetative body (thallus) lacks a cortex (ecorticate and is often immersed in the substrate or byssoid. The medulla is white, well defined, and often peppered with calcium oxalate crystals. Ascomata are not well defined, being cushions of soft white mycelium immersed in the medullary tissue, hence the name from the Greek krypto = "to conceal" and theke = "a container or sheath". It contains Trentepohlia, a green alga, as its photobiont partner.
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.
Herpothallon is a genus of crustose lichens in the family Arthoniaceae. It has about 50 species.
Herpothallon capilliferum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in China, it was formally described as a new species in 2022 by Pengfei Chen and Lulu Zhang. The type was collected from Dayang Lake Nature Reserve at an elevation of 1,405 m (4,610 ft); here the lichen was found growing on Nyssa sinensis. The main characteristics of the species are the presence of norstictic acid as a major lichen product, and the projecting hyphae of the pseudisidia. The species epithet capilliferum refers to this latter characteristic.
Herpothallon subglobosum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in China, it was formally described as a new species in 2022 by Pengfei Chen and Lulu Zhang. The type was collected in Baimaluo at an elevation of 2,100 m (6,900 ft). The lichen contains gyrophoric acid, lecanoric acid, and umbilicaric acid, which are lichen products that can be detected using thin-layer chromatography. The species epithet subglobosum refers to the somewhat spherical pseudisidia.
Herpothallon viridi-isidiatum is a species of crustose lichen in the family Arthoniaceae. Found in China, it was formally described as a new species in 2022 by Pengfei Chen and Lulu Zhang. The type was collected from the Baiyun Protection Station at an altitude of almost 1,300 m (4,300 ft); here, the lichen was found growing on the bark of Cunninghamia lanceolata. The species epithet viridi-isidiatum refers to the greenish-coloured pseudisidia. Gyrophoric acid, lecanoric acid, and umbilicaric acid are all lichen products that have been identified in this lichen.
Heiomasia is a genus of corticolous (bark-dwelling), crustose lichens in the family Graphidaceae. It has five species.
Herpothallon tricolor is a rare species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in South Brazil, it was described as a new species in 2017. It is distinguished from others species in genus Herpothallon by its unique colouration: a combination of a grey thallus with a bright red hypothallus and orange-tipped pseudoisidia.
Herpothallon pustulatum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. It was formally described as new to science in 2009 by the lichenologist Göran Thor. It is found in montane forests in Costa Rica, Brazil, and Venezuela. It contains confluentic acid as its major lichen product along with trace amounts of several other substances.
Herpothallon nigroisidiatum is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in Peru, it was formally described as new to science in 2009 by the lichenologist Göran Thor. It contains neodiffractic acid as its major lichen product, along with trace amounts of confluentic acid and chiodectonic acid. It is only known to occur at its type locality, which is a tropical rainforest in the Cordillera Escalera, San Martín. The species epithet nigroisidiatum refers to its pseudisidia, which have a black hypothallus that sometimes projects up into their inner parts and colours them black.
Herpothallon minimum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Originally described from specimens collected in Costa Rica, the lichen was formally described as new to science in 2009 by the lichenologists André Aptroot and Robert Lücking. It is also found in Africa and South America, in lower-elevation mountainous rainforests. Herpothallon minimum is the only species of Herpothallon that produces the substance 2'-O-methylperlatolic acid as its major secondary metabolite.
Herpothallon globosum is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in São Tomé and Príncipe, it was formally described as new to science in 2009 by the lichenologist Göran Thor. It contains psoromic acid and chiodectonic acid as major lichen products. The lichen is known only from two old collections made by Moller in 1885, at altitudes of 1,200 and 1,500 m. The species epithet refers to its numerous globose (spherical) and unbranched isidia.
Herpothallon fertile is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Originally described from specimens collected in Costa Rica, it was formally described as new to science in 2009 by the lichenologists André Aptroot and Robert Lücking. It also occurs in Brazil, and is considered by the authors to have a wide distribution in "tropical parts of America". Its species epithet fertile reflects the fact that it is the only species of Herpothallon to have been found with asci and ascospores.
Herpothallon elegans is a rare species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in Peru, it was formally described as new to science in 2009 by the lichenologist Göran Thor. It contains confluentic acid and lichexanthone as major lichen products. It is only known to occur in tropical rainforest at a couple of locations, with elevations of 850 m (2,790 ft) and about 1,200 m (3,900 ft).
Herpothallon echinatum is a species of corticolous (bark-dwelling) or lignicolous (wood-dwelling), crustose lichen in the family Arthoniaceae. Originally described from specimens collected in Costa Rica, it was formally described as new to science in 2009 by the lichenologists André Aptroot, Robert Lücking, and Susan Will-Wolf. It has also been recorded from a few locations in Asia and Australasia. It contain psoromic acid as a major lichen product.
Herpothallon confluenticum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Originally described from specimens collected in Thailand, it was formally described as new to science in 2009 by the lichenologists André Aptroot and Robert Lücking. The lichen has also been recorded in other localities in Asia, Australia, and South America. It contains confluentic acid as a major lichen product.
Herpothallon cinereum is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in Venezuela, it was formally described as new to science in 2009 by the lichenologist Göran Thor. It contains confluentic acid as its major lichen product. The lichen is only known to occur at its type locality in a tropical rainforest in Sierra Portuguesa (Lara) at an elevation of about 1,000 m (3,300 ft).
Herpothallon brialmonticum is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in Suriname, it was formally described as new to science in 2009 by the lichenologists André Aptroot and John Elix. The species epithet refers to the three novel lichen products found in the lichen: brialmontic acid, methylbrialmontic acid, and dimethylbrialmontic acid. In addition to these compounds, all related to brialmontin 2, the lichen also has confluentic acid as a major secondary metabolite. This neotropical lichen is only known to occur at the type locality.
Herpothallon adnatum is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in Peru, it was formally described as new to science in 2009 by the lichenologist Göran Thor. The type specimen was collected from Paucartambo,, at an elevation of 850 m (2,790 ft). The species is only known to occur at the type locality. It contains confluentic acid as its major lichen product, along with trace amounts of a few others.
