| Agyrium | |
|---|---|
 | |
| Agyrium rufum | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Pertusariales |
| Family: | Agyriaceae |
| Genus: | Agyrium Fr. (1822) |
| Type species | |
| Agyrium rufum | |
| Species | |
| Synonyms [1] | |
Agyrium is a genus of saprophytic fungi in the family Agyriaceae. It probably evolved from a lichen ancestor, as it is closely related to many lichenized species of fungi. [2]
Agyrium was first proposed by Elias Magnus Fries in his 1821 work Systema Mycologicum , [3] although the name was not published validly as a type species was not indicated; [4] Fries published the name validly a year later in the second volume of the same work. [5] The species Agyrium rufum was assigned as the type by Frederic Clements and Cornelius Lott Shear in 1931. [6]
Characteristics of genus Agyrium include the following: a poorly developed thallus that is immersed in its substrate; ascomata in the form of an apothecium with a reduced ring-shaped exciple (the layer surrounding the hymenium that sometimes develops into a distinct margin); paraphyses that are highly branched; and ascospores that are ellipsoid and thin-walled. [7]
The mycelia of Agyrium fungi, although not strictly lichenised, are associated with and sometimes penetrate green algae – particularly near the apothecia. [7] This is a condition that has been described as "facultative parasitism". [8]
As of May 2021 [update] , Species Fungorum accepts two species of Agyrium.
The type species, Agyrium rufum, has a largely Northern Hemisphere distribution and occurs widely in Europe, although it has also been recorded in Tasmania. [7] Agyrium aurantium occurs in China. [9]
Although 46 taxa have been placed in Agyrium since its inception, many of them were described more than a century ago and have not been investigated with modern molecular techniques. Several of them have since been transferred to other genera. For example: