''Harusavskia'' is single-species fungal

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 ...

in the family

Teloschistaceae The Teloschistaceae are a large family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The family, estimated to contain over 1800 species, was extensively revised in 2013, including the creation o ...

. It contains the little-known species ''Harusavskia elenkinianoides'', a saxicolous (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 in Chile.

Taxonomy

''Harusavskia elenkinianoides'' was formally described as a new species in 2017. The

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

was collected from the Laguna del Maule 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, or ...

. 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'', to which this lichen was first included. The species epithet alludes to a resemblance with '' Elenkiniana gomerana'', a lichen found in the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

Phylogenetically In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

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

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of the subfamily Teloschistoideae in the family

Description

In the genus ''Harusavskia'', the

thallus Thallus (plural: 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. Many of these organisms wer ...

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 t ...

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 (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 others some ...

, contains numerous oil droplets. 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 ...

(spore-bearing cells) typically contain eight spores. These spores are , with an undeveloped or only partially developed

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

(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 ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

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 exp ...

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