''Mycorrhaphium pusillum'' 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 ...

. It is a rare European fungus that has only been officially recorded a few times.

Taxonomy

The fungus was originally described as a species of '' Hydnum'' by Portuguese botanist

Félix Avelar Brotero Felix may refer to: * Felix (name), people and fictional characters with the name Places * Arabia Felix is the ancient Latin name of Yemen * Felix, Spain, a municipality of the province Almería, in the autonomous community of Andalusia, ...

in 1804.

Rudolph Arnold Maas Geesteranus Rudolf Arnold Maas Geesteranus (20 January 1911 in The Hague – May 18, 2003 in Oegstgeest), was a Dutch mycologist Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry ...

transferred it to the newly created genus ''

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 ...

'' in 1962. It has also been placed in ''

Hydnellum ''Hydnellum'' is a genus of tooth fungi in the family Bankeraceae (order Thelephorales). Widely distributed in the Northern Hemisphere, the genus contains around 40 species. The fruitbodies of its members grow by slowly enveloping nearby bits o ...

'' by

Petter Karsten Petter Adolf Karsten (16 February 1834 – 22 March 1917) was a Finnish mycologist, the foremost expert on the fungi of Finland in his day, and known in consequence as the "father of Finnish mycology". Karsten was born in Merimasku near Turku, s ...

in 1879, and ''

Steccherinum ''Steccherinum'' is a widely distributed genus of toothed crust fungi in the family Steccherinaceae. Taxonomy ''Steccherinum'' was circumscribed by Samuel Frederick Gray in his 1821 work ''A Natural Arrangement of British Plants''. Descripti ...

'' by

Howard James Banker Howard James Banker (April 19, 1866 – November 13, 1940) was an American mycology, mycologist. He received his PhD from Columbia University in 1908. Banker was an associate editor of the journal ''Mycologia'' starting from its establishment in 190 ...

in 1906.

Description

''Mycorrhaphium pusillum'' has a small

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 ...

with a rounded to fan-shaped cap measuring in diameter. Sometimes neighbouring caps fuse together during growth to make a larger conglomerate. The cap colour is pale

cream Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process ...

to pale yellowish, sometimes with regions that are pale brown. The pale cream stipe is long and thick. Spines on the underside of the cap are slender, numbering about 7 or 8 per millimetre, and are about a mm long. The mushroom has no distinct odour. The spores of ''M. pusillum'' are thin walled and more or less cylindrical, typically measuring 2.9–3.6 by 1.9–2.2

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 ...

. They usually contain an oil droplet. 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 the context is monomitic (containing only loosely arranged generative hyphae), although in the spines it is dimitic. The skeletal hyphae in the spines are thick walled, sometimes so much that they are almost solid, or with a small lumen. They are densely arranged in a parallel fashion, and usually measure 3.7–4.9 μm in diameter.

Habitat and distribution

A rare fungus, ''Mycorrhaphium pusillum'' is found only in Europe. It has been collected only a few times in southern and central Europe, and the first northern European collections were reported in 2015. In these latter collections, it was found fruiting on mossy ground in forest dominated by

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...

trees.

References

{{Taxonbar, from=Q42377895 Steccherinaceae Fungi of Europe Fungi described in 1805