''Zeroviella'' 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 ...

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

in the subfamily Xanthorioideae of 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 has eight

saxicolous A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, give ...

(rock-dwelling) species. ''Zeroviella'' was segregated from '' Rusavskia'', a closely related genus, in 2015.

Taxonomy

The genus was

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 ...

by lichenologists

Sergey Kondratyuk Sergey Yakovlevich Kondratyuk ( uk, Сергій Якович Кондратюк) (born 17 May 1959) is a Ukrainian botanist specialising in lichenology. His research deals with the taxonomy, floristics, ecology and geography of lichens and lic ...

and Jae-Seoun Hur in 2015, to contain the

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

centred around ''Rusavskia papillifera''. Accordingly, '' Zeroviella papillifera'' was assigned as the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus. According to their

phylogenetic 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 ...

analysis, these species formed a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

branch, warranting distinction as a new genus. Members of the genus ''Zeroviella'' exhibit distinct differences from those of the genus '' Rusavskia''. Notably, ''Zeroviella'' has cortical layers throughout the thallus, in contrast to ''Rusavskia'', which primarily features tissue with only a slight paraplectenchymatous layer. Additionally, the s of ''Zeroviella'' are noticeably thinner, attributed to the absence of a well-developed hollow in the

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of th ...

. This genus also typically displays pronounced

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 (pores on the cortex). While ''Zeroviella'' lobes appear convex due to their downward-bending edges, those of ''Rusavskia'' are extremely convex with a prominent hollow medulla. Geographically, ''Zeroviella'' is mainly found in

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

and Eastern

Eurasian Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

regions, whereas ''Rusavskia'' has a bipolar distribution (i.e., occurring at both

polar regions The polar regions, also called the frigid zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by float ...

) and is present at high altitudes across all continents. Phylogenetic analyses further distinguish the two, with ''Zeroviella'' positioned on a separate monophyletic branch. The genus name honours Ukrainian botanist Dmytro K. Zerov (1895–1971), "to acknowledge his contributions, especially to the Eurasian flora of liverworts and sphagnous mosses."

Description

''Zeroviella'' has a

foliose Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diverse ...

form and tends to grow on rocks. 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 ...

, or main body of the lichen, presents in vibrant shades ranging from yellow and orange to a deeper reddish-orange. It adheres firmly to its , attaching from its lower side. Its layers have a texture, while its medullary layer lacks a prominently developed cavity. The (reproductive structures) of ''Zeroviella'' are of the / type, with a that is in nature. When it comes to the reproductive , they manifest as narrowly elongated and rod-shaped (). Chemically, ''Zeroviella'' contains a dominant compound known as

parietin Parietin is the predominant cortical pigment of lichens in the genus '' Caloplaca'', a secondary product of the lichen ''Xanthoria parietina'', and a pigment found in the roots of Curled Dock (''Rumex crispus''). It has an orangy-yellow color and ...

, but the genus also contains other substances like teloschistin, fallacinal, and parietinic acid; traces of

emodin Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) is a chemical compound, of the anthraquinone family, that can be isolated from rhubarb, buckthorn, and Japanese knotweed (''Reynoutria japonica'' syn. ''Polygonum cuspidatum''). Emodin is particular ...

are present as well.

Habitat and distribution

The lichen genus ''Zeroviella'' thrives predominantly in coastal areas, often colonising large

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 ...

boulders. It can be found on both more or less vertical and horizontal rock surfaces that are sun-exposed. Beyond the coasts, ''Zeroviella'' extends to high-altitude mountainous regions, with a particular preference for areas featuring limestone

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial ...

s. The genus comprises eight species. Among these, ''Zeroviella papillifera'' is the most widespread. While ''Z. mandschurica'' and ''Z. esfahanensis'' are commonly found across the Asian continent, species like ''Z. coreana'', ''Z. digitata'', and ''Z. ussurica'' have a more limited range. ''Z. laxa'' was reported as new to Pakistan in 2021. In terms of its broader geographical spread, ''Zeroviella'' predominantly populates the

Palearctic The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Sibe ...

region, encompassing Europe, Asia, and North Africa. Although there are a few reports of ''Zeroviella papillifera'' being found in North America, these records require further verification.

Species

Species Fungorum ''Index Fungorum'' is an international project to index all formal names (scientific names) in the fungus kingdom. the project is based at the Royal Botanic Gardens, Kew, one of three partners along with Landcare Research and the Institute of Mi ...

(in the

Catalogue of life The Catalogue of Life is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxonomic Info ...

) accepts eight species of ''Zeroviella''. * '' Zeroviella coreana'' * '' Zeroviella digitata'' * '' Zeroviella domogledensis'' * '' Zeroviella esfahanensis'' * '' Zeroviella laxa'' * '' Zeroviella mandschurica'' * '' Zeroviella papillifera'' * '' Zeroviella ussurica''

References

{{Taxonbar, from=Q61980410 Teloschistales Teloschistales genera Lichen genera Taxa described in 2015 Taxa named by Sergey Kondratyuk Taxa named by Jae-Seoun Hur