''Psathyloma'' 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 ...

of two species of

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

-forming

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

Hymenogastraceae The Hymenogastraceae is a family of fungi in the order Agaricales with both agaric and false-truffle shaped fruitbodies. Formerly, prior to molecular analyses, the family was restricted to the false-truffle genera. The mushroom genus ''Psilocybe' ...

. Used informally among New Zealand-based mycologists since 1997, the genus was formally

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 2016 with '' Psathyloma leucocarpum'' as 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 ...

. The genus name, which combines ''

Psathyrella ''Psathyrella'' is a large genus of about 400 species, and is similar to the genera '' Coprinellus'', ''Coprinopsis'', ''Coprinus'' and ''Panaeolus'', usually with a thin cap and white or yellowish white hollow stem. The caps do not self digest ...

'' and ''

Hebeloma ''Hebeloma'' is a genus of fungi in the family Hymenogastraceae. Found worldwide, it contains the poison pie or fairy cakes ''(Hebeloma crustuliniforme)'' and the ghoul fungus ''( H. aminophilum)'', from Western Australia, which grows on rotting ...

'', alludes to the morphological similarity of the fruit bodies. Both species in ''Psathyloma'' are found in New Zealand, where they fruit on the ground in ''

Nothofagus ''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Gui ...

'' forests.

References

Agaricales genera Hymenogastraceae Fungi of New Zealand {{Hymenogastraceae-stub