''Mycorrhaphium citrinum'' is a species of

tooth fungus The hydnoid fungi are a group of fungi in the Basidiomycota with basidiocarps (fruit bodies) producing spores on pendant, tooth-like or spine-like projections. They are colloquially called tooth fungi. Originally such fungi were referred to the g ...

in the family

Steccherinaceae The Steccherinaceae are a family of about 200 species of fungi in the order Polyporales. It includes crust-like, toothed, and poroid species that cause a white rot in dead wood. Taxonomy The family was circumscribed by Czech mycologist Erast ...

that is found in Africa. It was described as a new species in 1989 by Norwegian mycologist

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 ...

. The type collection was made in Chati, a region in the Copperbelt Province in

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most cent ...

, where it was found growing in

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

Description

The

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 ...

of the fungus has a circular to fan-shaped of semicircular cap measuring in diameter. Its colour ranges from "citric yellow" (a feature for which it is named) to pale yellowish brown. The underside of the cap features pale yellow, densely crowded spines measuring 1–3 millimetre long. The spores, which measure 3–3.5 by 2–2.5

µm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

, have a shaped described as somewhat cylindrical to oblong-

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 ...

. They are smooth,

translucent In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions a ...

nonamyloid In mycology a tissue or feature is said to be amyloid if it has a positive amyloid reaction when subjected to a crude chemical test using iodine as an ingredient of either Melzer's reagent or Lugol's solution, producing a blue to blue-black stai ...

, and contain a small oil drop. Like other ''

Mycorrhaphium ''Mycorrhaphium'' is a genus of fungi in the family Steccherinaceae. The genus was circumscribed by Dutch mycologist Rudolph Arnold Maas Geesteranus in 1962. The type species is ''Mycorrhaphium adustum'' (formerly referred to '' Hydnum''). Fruit ...

'' species, the dimitic portion of 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 of ''M. citrinum'' is confined to the spines; the remainder of the context is monomitic. The skeletal hyphae are thick-walled, measuring 3–5 µm in diameter.

References

{{Taxonbar, from=Q43032428 Steccherinaceae Fungi of Africa Fungi described in 1989 Taxa named by Leif Ryvarden