''Franwilsia'' 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 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 three species.

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 ...

in 2014 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 ...

Ingvar Kärnefelt Jan Eric Ingvar Kärnefelt (born 1944) is a Swedish lichenologist. Early life and education Kärnefelt was born in Gothenburg, Sweden in 1944. His initial goal in his higher-level studies at University of Cologne in 1966–1967 was to become ...

, John Alan Elix, Arne Thell, and Jae-Seoun Hur. It contains species formerly included in the ''Caloplaca bastowii''-group; 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 ...

is ''Franwilsia bastowii''. The genus is in the subfamily Caloplacoideae in the Teloschistaceae. It forms a

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, ...

along with genus '' Eilifdahlia''. The genus name honours the reverend Francis Robert Muter Wilson, an early Australian lichenologist.

Description

''Franwilsia'' is characterized by a

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 ...

that can either be continuous or (broken into discrete areas). The cortical layer of the thallus is described as palisade , meaning it consists of tightly packed cells arranged in a

palisade A palisade, sometimes called a stakewall or a paling, is typically a fence or defensive wall made from iron or wooden stakes, or tree trunks, and used as a defensive structure or enclosure. Palisades can form a stockade. Etymology ''Palisade' ...

-like formation. The colour of the thallus ranges from whitish to grey or dark grey. The apothecia, or fruiting bodies, of ''Franwilsia'' are either or . The (a tissue layer beneath the spore-bearing

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 ...

), the lower portion of the hymenium, and the basal portion of the (the outer layer of tissue enclosing the spore-bearing layer) are densely interspersed with oil droplets or aggregations. The is leptodermatous paraplectenchymatous, indicating it is thin and made up of irregularly arranged cells. The of ''Franwilsia'' are , meaning they have two or chambers, and there are typically eight spores per

ascus 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 ...

. The

conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...

, or asexual spores, range from (rod-shaped) to narrowly bacilliform. 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 ...

(i.e., the K spot test), the thallus and apothecia show a purple reaction. Chemically, ''Franwilsia'' contains compounds such as

depside A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester bond. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, L ...

s of the brialmontin , anthraquinones of the parietin chemosyndrome, and lichexanthone, especially in the fruiting bodies of some species. In terms of similarities, ''Franwilsia'' closely resembles the genus '' Mikhtomia'' in having a hymenium, subhymenium, and basal portion of the true exciple rich in oil droplets. However, ''Franwilsia'' is differentiated by its specific structure of the true exciple and the presence of larger, irregular oil aggregations in the subhymenium. Additionally, ''Franwilsia'' is part of the Southern Hemisphere lichen flora, contrasting with ''Mikhtomia'', which is found in the Northern Hemisphere.

Species

Three species are accepted in ''Franwilsia'': * '' Franwilsia bastowii'' – Australia * ''

Franwilsia renatae ''Franwilsia'' is a genus of lichen-forming fungi in the family Teloschistaceae. It has three species. Taxonomy The genus was circumscribed in 2014 by lichenologists Sergey Kondratyuk, Ingvar Kärnefelt, John Alan Elix, Arne Thell, and Jae-Seo ...

'' – South Africa * '' Franwilsia skottsbergii'' – Chile A proposed Australian species ''Franwilsia kilcundaensis'' was not validly published by the authors.

References

{{Taxonbar, from=Q43199484 Teloschistales Teloschistales genera Taxa described in 2014 Taxa named by Sergey Kondratyuk Taxa named by Ingvar Kärnefelt Taxa named by John Alan Elix Taxa named by Arne Thell Taxa named by Jae-Seoun Hur