''Ryvardenia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the family

Polyporaceae The Polyporaceae () are a family (biology), family of polypore, poroid fungi belonging to the Basidiomycota. The trama (mycology), flesh of their basidiocarp, fruit bodies varies from soft (as in the case of the dryad's saddle illustrated) to v ...

. It contains two species, '' Ryvardenia campyla'' and the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

, ''

Ryvardenia cretacea ''Ryvardenia'' is a genus of fungi in the family Polyporaceae. It contains two species, '' Ryvardenia campyla'' and the type, '' Ryvardenia cretacea'' , formerly placed in the genus ''Polyporus''. ''Ryvardenia'' was circumscribed by Argentinian b ...

'' , formerly placed in the genus ''

Polyporus ''Polyporus'' is a genus of poroid fungi in the family Polyporaceae. Taxonomy Italian botanist Pier Antonio Micheli introduced the genus in 1729 to include 14 species featuring fruit bodies with centrally-placed stipes, and pores on the unders ...

''. ''Ryvardenia'' was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by Argentinian botanist Mario Rachenberg in 1994. The genus name of ''Ryvardenia'' is in honour of Leif Randulff Ryvarden (born 9 August 1935) who is a Norwegian

mycologist Mycology is the branch of biology concerned with the study of fungi, including their taxonomy, genetics, biochemical properties, and use by humans. Fungi can be a source of tinder, food, traditional medicine, as well as entheogens, poison, and ...

Molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

analysis of specimens from Argentina and Australia has shown that the species separate into two distinct

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s that are each restricted

biogeographically Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

to one side of the Pacific, suggesting that the taxa are speciating. However, there are no consistent morphological characteristics that can be used to distinguish between them, which according to Rajchenberg and Pildain "supports the maintenance of a complex but taxonomically single entity.

References

Polyporaceae Polyporales genera Taxa described in 1994 {{Polyporales-stub