''Obba'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of three species of poroid,

white rot A wood-decay or xylophagous fungus is any species of fungus that digests moist wood, causing it to rot. Some species of wood-decay fungi attack dead wood, such as brown rot, and some, such as ''Armillaria'' (honey fungus), are parasitic and col ...

crust fungi The corticioid fungi are a group of fungi in the Basidiomycota typically having effused, smooth basidiocarps (fruit bodies) that are formed on the undersides of dead tree trunks or branches. They are sometimes colloquially called crust fungi or p ...

in the family Gelatoporiaceae. The

genome sequence In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding g ...

of 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 specime ...

, '' O. rivulosa'', was reported in 2016.

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 2012 by mycologists Otto Miettinen and Mario Rajchenberg. The three species are members of the ''Cinereomyces'' clade, a grouping of

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 ...

ally related fungi distinct from the core polyporoid clade. '' O. rivulosa'' was introduced to science by

Miles Joseph Berkeley Miles Joseph Berkeley (1 April 1803 – 30 July 1889) was an English cryptogamist and clergyman, and one of the founders of the science of plant pathology. Life Berkeley was born at Biggin Hall, Benefield, Northamptonshire, and educated at R ...

and

Moses Ashley Curtis Moses Ashley Curtis (11 May 1808 – 10 April 1872) was a noted American botanist. Biography Curtis was born in Stockbridge, Massachusetts and educated at Williams College in Massachusetts. After graduating, he became a tutor for the children of ...

in 1869 as ''Polyporus rivulosus''. The

, '' O. valdiviana'', was originally described as a

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

of '' Ceriporiopsis rivulosa'' by Rajchenberg in 1995. The genus was formally transferred to the new family Gelatoporiaceae in 2017. The generic name ''Obba'' alludes to the similarity of the bottle-shaped cystidioles characteristic of the genus to the household containers for liquids used in Rome.

Description

''Obba'' species have crust-like

fruit bodies The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...

that are white (when young) or cream to ochre (when dry). They range in length from a few millimetres up to long, and are about 3 mm thick. ''Obba'' has a monomitic hyphal system, containing only generative hyphae, and these hyphae have

clamp connection A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of Basidiomycetes fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rec ...

Habitat and distribution

''Obba'' causes a

in the trunks of both

gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν ...

s and angiosperms. ''Obba'' species have been recorded in subtropical and boreal zones. ''O. valdiviana'' occurs in southern Argentina and Chile, and has been recorded a couple of times from Australia. ''O. rivulosa'' is found in the Caribbean, Europe, North America, and South America. '' O. thailandica'' was described from

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

in 2017. It was found growing on charred

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

wood.

References

{{Taxonbar, from=Q28432832 Fungi described in 2012 Gelatoporiaceae Polyporales genera