''Uncobasidium'' is a genus of two species of crust fungi in the

Meruliaceae The Meruliaceae are a family of fungi in the order Polyporales. According to a 2008 estimate, the family contains 47 genera and 420 species. , Index Fungorum accepts 645 species in the family. Taxonomy The family was formally circumscribed by E ...

family . 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 mycologists Kurt Hjorstam and

Leif Ryvarden Leif Randulff Ryvarden (born 9 August 1935) is a Norwegian mycologist. Early life and education Leif Ryvarden was born in Bergen as a son of Einar Norberg Johansen (1900–1959) and Hjørdis Randulff (1912–1975). He finished his secondary edu ...

in 1978 with the European fungus '' U. luteolum'' as the type species. The South American species '' U. roseocremeum'' was added to the genus in 2012. The distinguishing feature of ''Uncobasidium'' is the basal hook in the basidium.

Description

''Uncobasidium'' forms a crust-like

fruit body In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the Ovary (plants), ovary after flowering plant, flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their ...

, which is spread out on the surface of the

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism lo ...

. Its texture is softly membranous or byssoid (as if made of fibers). The

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

l system is monomitic, meaning it contains only generative hyphae. Individual hyphae are distinct when viewed with microscopy, and they range from thin to becoming thick walled, with

clamp connections 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), recei ...

. The hyphae of the subiculum are usually straight and of uniform diameter. In contrast, the hyphae of the subhymenium are twisty and sometimes strongly bent. The basidia (pleurobasidia) are roughly uniform (swollen at the base). They are strongly constricted with a hook-shaped appendage, arising in the basal

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 ...

, with four sterigmata. The spores of ''Uncobasidium'' fungi are

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

to obovate in shape, thin walled, and non- amyloid.

Species

*'' Uncobasidium luteolum'' Hjortstam & Ryvarden (1978) *'' Uncobasidium roseocremeum'' Gorjón, Gresl. & Rajchenb. (2013) Some species proposed for inclusion in ''Uncobasidium'' have been referred to other genera, including: *''Uncobasidium albidum'' (Hauerslev) Vesterh. (1996) = '' Aphanobasidium albidum'' (Hauerslev) Boidin & Gilles (1980) *''Uncobasidium calongei'' (Tellería) Hjortstam & Tellería (1990) = '' Cerocorticium calongei'' Tellería (1985) *''Uncobasidium notabile'' (H.S.Jacks.) Tellería (1995) = ''

Radulomyces notabilis ''Radulomyces'' is a genus of crust fungi in the family Radulomycetaceae. The genus has a widespread distribution and contains 11 species. It was circumscribed by Danish botanist Mads Peter Christiansen in 1960, with '' Radulomyces confluens'' ...

'' (H.S.Jacks.) Parmasto (1968)

References

{{Taxonbar, from=Q7882863 Meruliaceae Polyporales genera Taxa named by Leif Ryvarden Taxa described in 1978