''Myxarium'' 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 ...
of
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
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Hyaloriaceae
The Hyaloriaceae are a family of fungi in the order Auriculariales. Species within the family have gelatinous basidiocarps (fruit bodies) that produce spores on septate basidia and, as such, were formerly referred to the "heterobasidiomycetes" or ...
.
Basidiocarps
In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...
(fruit bodies) are gelatinous and effused or pustular. The genus is cosmopolitan. All species grow on dead wood or dead herbaceous stems.
Taxonomy
History
The genus was originally described by
Karl Friedrich Wilhelm Wallroth
Karl Friedrich Wilhelm Wallroth (13 March 1792 in Breitenstein – 22 March 1857 in Nordhausen) was a German botanist. His name is abbreviated Wallr. as a taxon authority.
He attended classes in medicine and botany at the University of Halle ...
in 1833 based on the visible white inclusions in the basidiocarps of the
type species
In International_Code_of_Zoological_Nomenclature, 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 spe ...
, ''
Myxarium nucleatum
''Myxarium nucleatum'' is a species of fungus in the family Hyaloriaceae. In the UK, it has been given the recommended English name of crystal brain. The fruit bodies are watery white, pustular or lobed, and gelatinous with small, white, mineral ...
'', which he interpreted as
spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s
[ (they are in fact crystals of ]calcium oxalate
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula or . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydr ...
). The genus was synonymized with '' Exidia'' by subsequent authors, until revived by Dutch mycologist M.A. Donk in 1966.basidia
A basidium (: basidia) is a microscopic spore-producing structure found on the hymenophore of reproductive bodies of basidiomycete fungi. The presence of basidia is one of the main characteristic features of the group. These bodies are also ...
with enucleate stalk cells ("myxarioid" basidia), a feature absent in ''Exidia''. Additional species were added to the genus on this basis.
Current status
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, ...
research, based on cladistic
Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...
analysis of DNA sequences
A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the ...
, indicates that ''Myxarium'' is distinct from ''Exidia'' and forms a natural (monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
) group of species related to the type.
References
{{Taxonbar, from=Q10592904
Auriculariales
Agaricomycetes genera