''Harusavskia'' is single-species fungal

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the family

Teloschistaceae The Teloschistaceae are a large family (biology), family of mostly lichen-forming fungi belonging to the class (taxonomy), class Lecanoromycetes in the division (botany), division Ascomycota. The family has a cosmopolitan distribution, althoug ...

. It contains the little-known species ''Harusavskia elenkinianoides'', a

saxicolous This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...

(rock-dwelling),

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 ...

. This species is known only from its original collection site near the

Laguna del Maule Laguna del Maule () is a lake located in the Andes of Central Chile Central Chile (''Zona central'') is one of the five natural regions into which CORFO divided continental Chile in 1950. It is home to a majority of the Chilean population ...

in Chile.

Taxonomy

''Harusavskia elenkinianoides'' was

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

as a new species in 2017. The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

was collected from the

in Chile at an elevation of , where it was found growing on

siliceous rock Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, o ...

. The genus name derives its name from two key characteristics. Firstly, it references the distinctive "" around the , a key feature in its spore structure. Secondly, the name pays homage to its resemblance to ''

Rusavskia elegans ''Rusavskia elegans'' (formerly ''Xanthoria elegans''), commonly known as the elegant sunburst lichen, is a lichenized species of fungus in the genus '' Rusavskia'', family Teloschistaceae. Recognized by its bright orange or red pigmentation, thi ...

'', to which this lichen was first included. The

species epithet Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In Taxonomy (biology), taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) ...

alludes to a resemblance with '' Elenkiniana gomerana'', a lichen found in the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

Phylogenetically In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

, genus ''Harusavskia'' is in the ''Filsoniana''

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

of the subfamily Teloschistoideae in the family

Description

In the genus ''Harusavskia'', the

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

is at the centre, meaning it has a cracked, patchy appearance, and transitions to a form at the edges with well-defined . The colour of the thallus ranges from yellow-brownish orange to brownish yellow-orange. The outer, or peripheral, portions are either or slightly shiny, featuring relatively few

pseudocyphella Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex) of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend ...

e – small, white, porous spots. In contrast, the central area has numerous pseudocyphellae, giving it an eroded appearance with a whitish-brownish yellow-orange hue. The thallus can grow to a diameter of several centimetres. The

apothecia An ascocarp, or ascoma (: ascomata), 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. As ...

(fruiting bodies) of ''Harusavskia'' are typically 0.4 to 1.3 mm in diameter and about 0.5 mm thick. They are in form. This means they have a – a rim that is similar in composition to the thallus – coloured yellowish-brownish orange, and a that is usually flat and dark brownish brick-orange. The , the layer just outside the reproductive cells, has a complex or globular cellular structure with very thin cell walls. The thalline exciple's cortical layer is composed of densely packed cells. The , the layer below the

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in oth ...

, contains numerous oil droplets. The asci (spore-bearing cells) typically contain eight spores. These spores are , with an undeveloped or only partially developed

septum In biology, a septum (Latin language, Latin for ''something that encloses''; septa) is a wall, dividing a Body cavity, cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Hum ...

(a dividing wall), visible only in their early stages. They are surrounded by a distinct halo that is 1 to 1.2 (up to 1.5)

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

wide when treated with a solution of

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

. Chemically, ''Harusavskia'' reacts distinctly to potassium hydroxide solution (i.e., the K

spot test Spot analysis, spot test analysis, or a spot test is a chemical test, a simple and efficient technique where analytic assays are executed in only one, or a few drops, of a chemical solution, preferably in a great piece of filter paper, without usin ...

). The thallus turns purple, while the (the top layer above the hymenium) and the cortical layer of the thalline exciple change to a bright crimson purple. The cortex of the thalline section reacts by turning bluish, violet, or ink-purple.

Habitat and distribution

At the time of its original publication, ''Harusavskia elenkinianoides'' was known to occur only at its type locality in Chile, where it grows on siliceous rock.

References

{{Taxonbar, from=Q43957174 , from2=Q43960416 Teloschistales Teloschistales genera Lichen genera Taxa described in 2017 Taxa named by Sergey Kondratyuk