The Leotiomycetes are a class of ascomycete fungi. Many of them cause serious plant diseases.
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 Collemataceae are a lichenized family of fungi in the order Peltigerales. The family contains ten genera and about 325 species. The family has a widespread distribution.
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.
The Mycocaliciaceae are a family of seven genera and about 90 species of fungi in the order Mycocaliciales.
Calicium is a genus of leprose lichens. It is in the family Caliciaceae, and has 40 species.
Acolium is a genus of lichenized fungi in the family Caliciaceae. The genus has a widespread distribution and contains six species. These lichens are found on bark and wood, occasionally on rocks, or growing on other lichens.
Roccella is a genus of 23 species of lichens in the family Roccellaceae. The genus was circumscribed by Swiss botanist Augustin Pyramus de Candolle in 1805, with Roccella fuciformis as the type species.
Placidium is a genus of crustose to squamulose to almost foliose lichens. The genus is in the family Verrucariaceae. Most members grow on soil, but some grow on rock (saxicolous). The fruiting bodies are perithecia, flask-like structures immersed in the lichen body (thallus) with only the top opening visible, dotting the thallus. Lichen spot tests are all negative. Members of the genus lack rhizines, but otherwise resemble members of the genus Clavascidium.
The Caliciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. Although the family has had its classification changed several times throughout its taxonomic history, the use of modern molecular phylogenetic methods have helped to establish its current placement in the order Caliciales. Caliciaceae contains 39 genera and about 670 species. The largest genus is Buellia, with around 300 species; there are more than a dozen genera that contain only a single species.
Bunodophoron is a genus of lichen-forming fungi in the family Sphaerophoraceae.
Calicium viride, commonly known as the green stubble lichen, is a species of pin lichen in the family Caliciaceae, and the type species of the genus Calicium. It is a common and widely distributed species in temperate areas of the Northern Hemisphere and southern South America.
Allocalicium is a single-species fungal genus in the family Caliciaceae. It is monotypic, containing the single pin lichen species Allocalicium adaequatum. This lichen occurs in North America, South America, Europe, and the Russian Far East, where it grows on branches and twigs of deciduous trees and shrubs, typically those of alder and poplar. The species was originally described in 1869 as a member of Calicium, but molecular phylogenetics analysis demonstrated it was not a member of that genus and so Allocalicium was created to contain it.
Calycidium is a genus of lichen-forming fungi in the family Sphaerophoraceae. It has two species. It is one of the few lichen genera containing foliose (leafy) species that produce a mazaedium – a powdery mass of spores. Both species occur in Australasia and South America, where they grow on tree bark or on mosses.
Calicium carolinianum is a species of lichen in the family Caliciaceae. It is endemic to the Gulf Coastal Plain region of the United States. The lichen contains norstictic acid, and has ascospores that measure 13–17 by 8–9 μm.
Calicium pinicola is a species of lignicolous (wood-dwelling), crustose lichen in the family Caliciaceae. It is widely distributed in Europe, and also occurs in the United States.
Sagiolechiaceae is a small family of lichen-forming fungi in the order Ostropales. It contains two genera, Rhexophiale, and Sagiolechia, the type genus. The family was circumscribed in 2010 by lichenologists Elisabeth Baloch, Robert Lücking, H. Thorsten Lumbsch, and Mats Wedin. Molecular phylogenetic analysis showed that the two genera formed a distinct clade in Ostropales. Four species were included in the original circumscription of the family.
Rostania is a genus of lichen-forming fungi in the family Collemataceae. These lichens are primarily found on tree bark, occasionally on wood, with one species known to inhabit soil. The genus is characterized morphologically by having minute thalli made of hyphal tissue without a separate cortex, and the more or less cuboid-shaped ascospores.
Pseudothelomma ocellatum is a species of lignicolous (wood-dwelling), crustose lichen in the family Caliciaceae. This lichen is characterised by its grey, areolate thallus that produces abundant lichenised diaspores, such as short spherical isidia and coarse, dark brown-black soredia. It is typically sterile, meaning apothecia are absent.
Pseudothelomma occidentale is a species of corticolous (bark-dwelling), crustose lichen in the family Caliciaceae. It was first formally described by Albert William Herre in 1910, who initially classified it in the genus Cyphelium. Leif Tibell transferred it to Thelomma in 1976. In 2016, María Prieto and Mats Wedin transferred the taxon to the newly circumscribed genus Pseudothelomma.
