''Psilolechia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of four species of

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...

s. It is the only member of Psilolechiaceae, a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

that was created in 2014 to contain this genus.

Taxonomy

The genus ''Psilolechia'' was established by

Abramo Bartolommeo Massalongo Abramo Bartolommeo Massalongo (13 May 1824 – 25 May 1860) was an Italian paleobotanist and lichenologist. He was born in Tregnago in the Province of Verona and took a great interest in botany as a young man. Massalongo joined the faculty of med ...

in 1860. Formerly classified in the family

Pilocarpaceae The Pilocarpaceae are a family of crustose lichens in the order Lecanorales. The species of this family have a cosmopolitan distribution and have been found in a variety of climatic regions. Pilocarpaceae was circumscribed by Alexander Zahlbruck ...

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis showed that ''Psilolechia'' represented a distinct

lineage Lineage may refer to: Science * Lineage (anthropology), a group that can demonstrate its common descent from an apical ancestor or a direct line of descent from an ancestor * Lineage (evolution), a temporal sequence of individuals, populati ...

that deserved placement at the familial level, the Psilolechiaceae, which was formally

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in 2014. This arrangement was accepted in later large-scale updates of fungal classification. Psilolechiaceae is in the order

Lecanorales The Lecanorales are an order of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The order contains 26 families, 269 genera, and 5695 species. Families * Aphanopsidaceae * Biatorellaceae * Brigan ...

, in the suborder Sphaerophorineae, which also includes the families

Psoraceae The Psoraceae are a family of lichenized fungi in the order Lecanorales. The Austrian Botanist and Lichenologist Alexander Zahlbruckner first described the family in 1898. Species of this family have a widespread distribution. Genera This is a ...

, and

Ramalinaceae The Ramalinaceae are a family of lichenized fungi in the order Lecanorales. The family name is synonymous with the name ''Bacidiaceae''. Species of this family have a widespread distribution. Genera *''Aciculopsora'' *''Adelolecia'' *'' Arthro ...

Description

Psilolechiaceae is a monogeneric family of

s with effuse, ecorticate (lacking a

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

), leprose thalli formed by goniocysts (aggregations of

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e) containing ''

Trebouxia ''Trebouxia'' is a unicellular green alga.Silverside, A. J. (2009). Retrieved from http://www.bioref.lastdragon.org/Chlorophyta/''Trebouxia''.html It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and ...

'' or stichococcoid algae. The

apothecia An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...

lack a distinct margin, and the

asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

are 8-spored and have a cylindrical to clavate shape. They feature a central, elongated tube-like structure, and a non-

amyloid Amyloids are aggregates of proteins characterised by a Fibril, fibrillar morphology of 7–13 Nanometer, nm in diameter, a beta sheet (β-sheet) Secondary structure of proteins, secondary structure (known as cross-β) and ability to be Staining, ...

ascus wall surrounded by a thin outer layer. Both the tube-like structure and the thin outer layer

stain A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials app ...

dark blue in K/I.

Ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s are oblong-ovoid to tear-shaped, simple (rarely 1-septate in ''P. leprosa''), and

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

Species

''Psilolechia'' contains four species: *''

Psilolechia clavulifera ''Psilolechia'' is a genus of four species of crustose lichens. It is the only member of Psilolechiaceae, a family that was created in 2014 to contain this genus. Taxonomy The genus ''Psilolechia'' was established by Abramo Bartolommeo Massalong ...

'' (Nyl.) Coppins (1983) – widespread *'' Psilolechia leprosa'' Coppins & Purvis (1987) – north-west Europe; Greenland *''

Psilolechia lucida ''Psilolechia lucida'' is a species of saxicolous lichen in the family Psilolechiaceae. It is widely distributed through the world, where it grows on natural and artificial rocky substrates in the shade, often in sheltered underhangs. It forms a ...

'' (Ach.) M.Choisy (1949) – widespread *''

Psilolechia purpurascens ''Psilolechia'' is a genus of four species of crustose lichens. It is the only member of Psilolechiaceae, a family that was created in 2014 to contain this genus. Taxonomy The genus ''Psilolechia'' was established by Abramo Bartolommeo Massalong ...

'' Coppins & Purvis (1987) –

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

''Psilolechia'' species grow in locations that are humid and shaded. ''P. leprosa'' tends to grow on mineral-enriched rocks and

siliceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

rocks, and is often recorded around old mines.

References

{{Taxonbar, from1=Q7256032, from2=Q28872150 Lecanorales Lichen genera Lecanorales genera Taxa named by Abramo Bartolommeo Massalongo Taxa described in 1860