A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not plants. They may have tiny, leafless branches (fruticose); flat leaf-like structures (foliose); grow crust-like, adhering tightly to a surface (substrate) like a thick coat of paint (crustose); have a powder-like appearance (leprose); or other growth forms.
Chaenotheca is a genus of lichenized fungi within the family Coniocybaceae. The sexual reproduction structures are a mass of loose ascospores that are enclosed by a cup shaped exciple sitting on top of a tiny stalk, having the appearance of a dressmaker's pin, hence the common name pin lichen. Genus members are also commonly called needle lichens.
Steven B. Selva is Professor Emeritus of Biology and Environmental Studies at the University of Maine at Fort Kent, a world-renowned lichenologist, and curator of UMFK's lichen herbarium. Selva is an expert on stubble lichens of the order Caliciales, called so because their millimeter-high stalks resemble beard stubble.
The Lecanoraceae are a family of lichenized fungi in the order Lecanorales. Species of this family have a widespread distribution.
The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose (bushy), and squamulose (scaly) representatives. Several characteristics of the spore-bearing structures, the ascomata, define the family, including their perithecioid form–more or less spherical or flask-shaped, with a single opening and otherwise completely enclosed by a wall. Squamulose members of the Verrucariaceae with simple ascospores, and without algae in the spore-bearing region are known as catapyrenioid lichens; there are more than 80 of these species. The family has several dozen lichenicolous (lichen-dwelling) examples, and a few genera that contain solely lichenicolous members. An unusually diverse variety of photobiont partners have been recorded, mostly green algae, but also brown algae and yellow-green algae.
Bulbothrix is a genus of lichen-forming fungi in the family Parmeliaceae. This genus is synonymous with Bulbothricella V.Marcano, S.Mohali & A.Morales. Bulbothrix was circumscribed by lichenologist Mason E. Hale in 1974 with Bulbothrix semilunata as the type species.
David Leslie Hawksworth is a British mycologist and lichenologist currently with a professorship in the Universidad Complutense de Madrid in Madrid, Spain and also a Scientific Associate of The Natural History Museum in London. In 2002, he was honoured with an Acharius Medal by the International Association for Lichenology. He married Patricia Wiltshire, a leading forensic ecologist and palynologist in 2009. As of 2022, he is the Editor-in-Chief of the journals IMA Fungus and Biodiversity and Conservation.
Chaenothecopsis is a genus of about 40 species of pin lichens in the family Mycocaliciaceae. Many of the species are resinicolous, meaning they grow on conifer resin or other plant exudates. Most common host plants are trees in the genera Abies, Picea, and Tsuga.
Phaeocalicium is a genus of lichen-forming fungi in the family Mycocaliciaceae. The genus was circumscribed in 1970 by German lichenologist Alexander Schmidt, with Phaeocalicium praecedens assigned as the type species.
Stenocybe is a genus of fungi in the family Mycocaliciaceae. It has 14 species.
Sphinctrina is a genus of lichenicolous fungi, usually not lichenized, in the family Sphinctrinaceae. Its species are most commonly parasitic on lichens of the genus Pertusaria.
Psilocybe hispanica is a species of fungus in the family Hymenogastraceae. It produces small brown mushrooms with conical to convex caps up to 10 mm (0.4 in) in diameter and stems 16 to 25 mm long by 0.5 to 1 mm thick. Reported as new to science in 2000, it is only known from the Pyrenees mountain range in northern Spain and southwestern France, where it grows on horse dung in grass fields at elevations of 1,700 to 2,300 m. The mushroom contains the psychoactive compound psilocybin. The possible depiction of this species in the 6,000-year-old Selva Pascuala rock art suggests that it might have been used in ancient religious rituals—the oldest evidence of such usage in prehistoric Europe.
Dictyonema is a genus of mainly tropical basidiolichens in the family Hygrophoraceae.
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 36 genera and about 600 species. The largest genus is Buellia, with around 300 species; there are more than a dozen genera that contain only a single species.
A lichenicolous fungus is a parasitic fungus that only lives on lichen as the host. A lichenicolous fungus is not the same as the fungus that is the component of the lichen, which is known as a lichenized fungus. They are most commonly specific to a given fungus as the host, but they also include a wide range of pathogens, saprotrophs, and commensals. It is estimated there are 3000 species of lichenicolous fungi. More than 1800 species are already described among the Ascomycota and Basidiomycota. More than 95% of lichenicolous fungi described as of 2003 are ascomycetes, in 7 classes and 19 orders. Although basidiomycetes have less than 5% of lichenicolous lichen species, they represent 4 classes and 8 orders. Many lichenicolous species have yet to be assigned a phylogenetic position as of 2003.
Buelliella lecanorae is a species of lichenicolous (lichen-eating) fungus in the class Dothideomycetes. It is found in a few locations in Estonia and in Crimea, where it grows parasitically on members of the Lecanora subfusca species group.
Graphium samogiticum is a little-known species of lichenicolous (lichen-eating) fungus in the family Microascaceae. It is found in Lithuania, where it parasitises two lichen species that inhabit abandoned gravel pits.
Pseudocyphellaria glabra is a species of corticolous (bark-dwelling), foliose lichen in the family Peltigeraceae. It has a pale-green upper thallus surface, a white medulla and white pseudocyphellae.
Myriochapsa is a genus of corticolous (bark-dwelling), crustose lichens in the subfamily Graphidoidae of the family Graphidaceae. It has three species. The genus was circumscribed in 2013 by Marcela Cáceres, Robert Lücking, and H. Thorsten Lumbsch, with the Brazilian Myriochapsa psoromica assigned as the type species. The generic name combines Myriotrema and Chapsa, referring to the two Graphidaceae genera that it resembles. The main distinguishing characteristics of the new genus are its densely corticate thallus, and the presence of the lichen product psoromic acid. Additionally, its apothecia have wider pores, with differently textured margins. Although originally created as a monotypic genus, Harrie Sipman added two South American species in 2014.
Crittendenia is a genus of lichenicolous (lichen-dwelling) fungi in the monogeneric family Crittendeniaceae. The genus was circumscribed in 2021 to contain two species, C. lichenicola, and the type, C. coppinsii. An additional 16 species were added to the genus the following year. The genus name honours British lichenologist Peter Crittenden.
