''Varicellaria'' is a
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 ...
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 genus in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Varicellariaceae.
Taxonomy
The genus ''Varicellaria'' was
circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle.
* Circum ...
by Finnish lichenologist
William Nylander
William Andrew Michael Junior Nylander Altelius (born 1 May 1996) is a Swedish professional ice hockey Forward (ice hockey), forward for the Toronto Maple Leafs of the National Hockey League (NHL). Nylander was selected by the Maple Leafs in t ...
in 1858, with ''
Varicellaria microsticta'' assigned as the
type species
In International_Code_of_Zoological_Nomenclature, 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 spe ...
.
The family Varicellariaceae, containing only the
type genus
In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name.
Zoological nomenclature
According to the International Code of Zoological Nomenclature, "The name-bearin ...
''Varicellaria'', was informally proposed by Brendan Hodkinson, Richard Harris, and James Lendemer in 2011.
H. Thorsten Lumbsch and Steven Leavitt formally published the family in 2018.
However, the taxon was not
validly published because "an identifier issued by a recognized repository was not cited in the protologue", contrary to rules of
botanical nomenclature
Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy (biology), taxonomy. Plant taxonomy is concerned with grouping and classifying plants; Botany, botanical nomenclature then provides na ...
.
This nomenclatural oversight was rectified later the same year in a separate publication.
Description
Characteristics of the family Varicellariaceae are similar to those of its genus. These are: a crustose thallus, unicellular
green alga
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( ...
l
photobiont
A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship. s from genus ''
Trebouxia
''Trebouxia'' is a unicellular green alga. It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and temperate regions.Erokhina, L. G., Shatilovich, A. V., Kaminskaya, O. P., & Gilichinskii, D. A. (2004 ...
'',
ascomata
An ascocarp, or ascoma (: ascomata), is the fruiting body (sporocarp (fungi), sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded ascus, asci, each of which typically contains four to ...
in the form of disc-like
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 ...
, non-
amyloid
Amyloids are aggregates of proteins characterised by a fibrillar morphology of typically 7–13 nm in diameter, a β-sheet secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. In the human ...
gel in 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 ...
, strongly amyloid, one- or two-spored
asci, and
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from , and .
Histopathology
Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...
, thick-walled, one-layered, one- or two-celled
ascospore
In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...
s.
''Varicellaria'' species are characterised by a pale bluish-grey or whitish grey
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 ...
, which can be smooth and thin or cracked and thick. They typically have convex
soralia
Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria or g ...
that are paler or the same colour as the thallus.
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) are rare in these species.
Varicellaria species are associated with
green algae
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...
from the genus ''
Trebouxia
''Trebouxia'' is a unicellular green alga. It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and temperate regions.Erokhina, L. G., Shatilovich, A. V., Kaminskaya, O. P., & Gilichinskii, D. A. (2004 ...
''. Specifically, they have been found to associate with ''Trebouxia'' sp. OTU A03.
The major
secondary metabolite
Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...
in ''Varicellaria'' species is
lecanoric acid. Some specimens may also contain
variolaric acid, but its presence is not a reliable diagnostic feature for species identification.
Habitat and distribution
Collectively, the species in genus ''Varicellaria'' have a
cosmopolitan distribution
In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...
.
''Varicellaria'' species show diverse preferences. Some species, like ''V. hemisphaerica'', are primarily
corticolous
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 ...
(growing on bark), while others, such as ''V. lactea'', are
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 ...
(growing on rocks). These habitat preferences play a crucial role in species delimitation.
Species
Recent
molecular phylogenetics
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 ...
studies have helped clarify species boundaries within ''Varicellaria''. These studies have shown that substrate preference and soredia size are important factors in distinguishing between species. Molecular data, combined with morphological and chemical characteristics, have proven essential for accurate species identification.
As of 2024, there are 12 recognised species in the genus ''Varicellaria'':
*''
Varicellaria culbersonii''
*''
Varicellaria emeiensis''
– China
*''
Varicellaria hemisphaerica''
*''
Varicellaria kasandjeffii''
*''
Varicellaria lactea''
*''
Varicellaria microsticta''
*''
Varicellaria philippina''
*''
Varicellaria rhodocarpa''
*''
Varicellaria velata''
*''
Varicellaria cacuminuminum''
References
{{Taxonbar, from=Q10713040
Pertusariales
Pertusariales genera
Lichen genera
Taxa described in 1858
Taxa named by William Nylander (botanist)