| Watsoniomyces | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lichinomycetes |
| Order: | Lichinales |
| Family: | Lichinaceae |
| Genus: | Watsoniomyces D.Hawksw., M.Powell & T.Sprib. (2021) |
| Species: | W. obsoletus |
| Binomial name | |
| Watsoniomyces obsoletus (Nyl.) D.Hawksw., M.Powell & T.Sprib. (2021) | |
| Synonyms [1] | |
| |
Watsoniomyces is a single-species fungal genus in the family Lichinaceae. It contains the saxicolous (rock-dwelling) crustose lichen Watsoniomyces obsoletus.
The genus was circumscribed in 2021 by David Hawksworth, Mark Powell, and Toby Spribille to contain the species formerly known as Lecidea lichenicola. Molecular phylogenetic analysis showed that the species belonged to the family Lichinaceae in the order Lichinomycetes. The original material of Lecidea lichenicola was examined and determined to actually be a different species, Trapelia glebulosa . Further research showed that the earliest available name for this lichen is Lecidea obsoleta (originally described by William Nylander in 1865 [2] ), and so a modern collection was used to neotypify the species. Watsoniomyces obsoletus grows on chalk pebbles, and is the first known member of the Lichinomycetes that has an endolithic thallus. [3]
Genus Watsoniomyces stands out from all other known genera in the order Lichinomycetes because it has a thallus (the main body of the lichen) that grows inside rock surfaces (endolithic), unlike others that typically have a crusty (crustose) or slightly scaly ( subsquamulose ) surface or even a shrub-like (fruticose) growth. [3]
The prodominant photobiont partner is a cyanobacterium belonging to Scytonema , but it has also been found partnered with algae that have orange-pigmented chloroplasts (perhaps Trentepohlia ), and also with clusters of green algal cells similar to Chlorella . [3]
Watsoniomyces obsoletus typically grows on chalk pebbles found in disturbed environments, such as near rabbit burrows or in areas where the ground has been scraped, revealing chalk fragments on the surface. This species particularly favours smaller pebbles, no larger than 10 cm. It forms part of a unique community of various verrucarioid species and has been classified in the Lecideetum watsoniae group, based on studies conducted in Hertfordshire, Norfolk, Surrey, and Sussex. [3]
This lichen is confirmed to exist only in southern and eastern England, with sightings in Bedfordshire, Buckinghamshire, Cambridgeshire, Hertfordshire, the Isle of Wight, Norfolk, Surrey, Sussex, and Yorkshire. Over the past 50 years, it has disappeared from several locations in southern England, likely due to a decrease in rabbit grazing which allowed for more scrub growth. Despite being categorised as "least concern" and "nationally scarce" in British lichen conservation evaluations, Watsoniomyces obsoletus is considered significant for conservation as it is potentially endemic to the UK. It is suspected that this species might also be found on the French side of the English Channel, although it has not yet been reported from France or any other region. [3]
A lichen is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungi species, along with a yeast embedded in the cortex or "skin", in a mutualistic relationship.
Lichinales is the sole order of ascomycete fungi in the class Lichinomycetes. It contains three families: Gloeoheppiaceae, Lichinaceae, and Peltulaceae. Most species are lichenized. Lichinales was proposed in 1986 by German lichenologists Aino Henssen and Burkhard Büdel. The class Lichinomycetes was created by Valérie Reeb, François Lutzoni and Claude Roux in 2004.
Gloeoheppiaceae is a family of ascomycete fungi in the order Lichinales. The family contains ten species distributed amongst three genera. Most species are lichenised with cyanobacteria. Species in this family are mostly found in desert areas. Modern molecular phylogenetics analysis casts doubt on the phylogenetic validity of the family, suggesting a more appropriate placement of its species in the family Lichinaceae.
The Lichinaceae are a family of ascomycete fungi. Most species are lichenized with cyanobacteria, and have a distribution largely in temperate regions.
Calvitimela is a lichen genus in the family Tephromelataceae. Members of the family Tephromelataceae are crustose lichens with green photobionts and lecideine or lecanorine apothecia. The species in Calvitimela have lecideine apothecia, are saxicolous and are primarily found in alpine to arctic regions.
The Lecideaceae are a family of lichen-forming fungi in the order Lecideales. It contains about 30 genera and roughly 250 species. A major distinguishing characteristic of the family is the lecanoroid form of the fruiting bodies: typically circular, dark, and without a thalline margin. Most species in the family are lichenised with green algae, although a few species, scattered amongst several genera, are lichenicolous—they live on other lichens. Lecideaceae lichens tend to grow on rocks, wood, and soil. Several Lecideaceae species accelerate the weathering of rock surfaces, a process known as pedogenesis, by extending their hyphae into cracks and expelling rock flakes. This contributes to significantly faster weathering rates in certain environments, impacts various materials from natural rocks to man-made Sekishu roof tiles, and involves key biomolecules identified for survival and biodeterioration, including compounds to withstand intense ultraviolet radiation.
Crustose lichens are lichens that form a crust which strongly adheres to the substrate, making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes.
Hydropunctaria is a genus of saxicolous (rock-dwelling), crustose lichens in the family Verrucariaceae. The genus includes both aquatic and amphibious species, with members that colonise either marine or freshwater habitats. The type species, Hydropunctaria maura, was formerly classified in the large genus Verrucaria. It is a widely distributed species common to littoral zones. Including the type species, five Hydropunctaria lichens are considered marine species: H. adriatica, H. amphibia, H. aractina, H. orae, and H. oceanica.
Schaereria is a genus of lichen-forming fungi. It is the sole genus in the family Schaereriaceae, which itself is the only family in the Schaereriales, an order in the subclass Ostropomycetidae of the class Lecanoromycetes. Most Schaereria species are crustose lichens that live on rocks. Schaereria was first proposed by Gustav Wilhelm Körber in 1855 and was later taken up by other lichenologists despite periods of disuse.
Atrophysma is a fungal genus in the family Pannariaceae. It contains the single species Atrophysma cyanomelanos, a crustose lichen found only in Alaska.
Porpidia seakensis is a species of crustose lichen in the family Lecideaceae. It is an endolithic species, meaning it grows inside the rocks, between the grains. Found only in Alaska, it was formally described as a new species in 2020 by British lichenologist Alan Fryday. The type specimen was collected in the Hoonah-Angoon Census Area, in Glacier Bay National Park. Here it was discovered growing on granitic rock in a woodland. The lichen is only known from this area, although it is locally common. Its preferred habitat is siliceous rocks and boulders in wooded areas that are open and well lit. The specific epithet seakensis uses the letters "seak" to refer to a standard abbreviation for southeast Alaska.
Lambiella aliphatica is a species of crustose lichen in the family Xylographaceae. Found in Alaska, it was described as a new species in 2020 by Toby Spribille and Philipp Resl. The type specimen was collected in the Hoonah-Angoon Census Area of Glacier Bay National Park. Here it was found at an altitude of 907 m (2,976 ft) growing on an argillite rock in alpine scree. The specific epithet aliphatica refers to the unidentified fatty acids that are present in the thallus. It is the first member of genus Lambiella to contain primarily fatty acids in the thallus. Lambiella globulosa is similar in morphology, but this species contains stictic acid rather than fatty acids as the primary secondary metabolite.
Sagiolechia phaeospora is a species of crustose lichen in the family Sagiolechiaceae. It is found in the alpine tundra of Alaska.
Lecidea streveleri is a species of crustose lichen in the family Lecideaceae. Found in Canada and the United States, it was described as a new species in 2020 by lichenologist Toby Spribille. The type specimen was collected in the Hoonah-Angoon Census Area of Glacier Bay National Park (Alaska). Here it was on steep slopes in a basin on the west side of Dundas Bay, growing on the bark of an alder tree. The specific epithet streveleri honors Dr. Gregory P. Streveler, who, according to Spribille, is "an extraordinary naturalist and polymath, and author of numerous scientific papers, who has dedicated much of his life to understanding the natural history of Glacier Bay".
Toensbergia blastidiata is a species of crustose lichen in the family Sporastatiaceae. Found in northwestern North America, it was described as a new species in 2020 by the lichenologists Toby Spribille and Tor Tønsberg. The type specimen was collected in Glacier Bay National Park at the base of Marble Mountain (Alaska). Here the lichen was found growing on the bark of Alnus viridis subsp. crispa. The specific epithet blastidiata refers to the "blastidiate thallus surface"; blastidia are vegetative propagules containing both mycobiont and photobiont, which are produced by yeast-like "budding".
Harpidiaceae is a small family of lichen-forming fungi, containing two genera and five species. It is of uncertain classification in the Pezizomycotina.
The following outline provides an overview of and topical guide to lichens.
Opegrapha physciaria is a species of lichenicolous (lichen-dwelling) fungus in the family Opegraphaceae. It was first formally described as a new species in 1897 by Finnish lichenologist William Nylander, who placed it in the genus Lecidea. David Hawksworth and Brian J. Coppins transferred it to the genus Opegrapha in 1992.
Myochroidea is a genus of lichen-forming fungi of uncertain familial placement in the order Lecanorales. It has four species of grey or brown-grey crustose lichens.
Puttea is a genus of lichen-forming fungi with uncertain familial placement in the order Lecanorales. The genus comprises four species. Finnish lichenologists Soili Stenroos and Seppo Huhtinen established the genus Puttea in 2009 for the lichen species formerly known as Lecidea margaritella, which has undergone various reclassifications. Molecular phylogenetics analyses have shown that Puttea margaritella does not align closely with genera like Fellhanera or Micarea, but its precise familial placement remains uncertain. Puttea is characterized by an indistinct, lichenized thallus composed of delicate fungal filaments and small algal cells. Its minute, round, whitish apothecia lack a distinct margin, and the asci, or spore-producing cells, are thick-walled, club-shaped, and contain eight spores, showing specific reactions with iodine-based stains. The type species of the genus, Puttea margaritella, typically inhabits boreal forests, growing on the liverwort species Ptilidium pulcherrimum and sometimes on decaying wood or bark. Initially thought to be confined to Europe, it has since been found in North America, particularly in Alaska and Québec, extending its known range. The species is parasitic, damaging its host, and is considered rare within its distribution.