Archaeorhizomycetes is a

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently ...

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 fr ...

in the subdivision

Taphrinomycotina The Taphrinomycotina are one of three subdivisions constituting the Ascomycota (fungi that form their spores in a sac-like ascus) and is more or less synonymous with the slightly older invalid name Archiascomycetes (sometimes spelled Archaeascomy ...

of the

Ascomycota Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ...

. So far, the class has only one described

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

, Archaeorhizomycetales,

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

, Archaeorhizomycetaceae, and

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

, ''Archaeorhizomyces''. The class was first described by a team led by Anna Rosling in 2011. Species in the class are globally distributed, and grow in soil and around roots. Specific known host trees of various Archaeorhizomyces species include hemlock,

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfam ...

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

and heather, but other species colonise

hardwood Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...

s generally. The precise ecological role of the taxa is uncertain. While originally found to be seasonal, suggesting it was dependent on carbon compounds from the roots, when grown in culture, ''Archaeorhizomyces finlayi'', was shown to be able to grow using either

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...

as its sole source of carbon, suggesting "that it may be involved in decomposition and not require direct carbon transfer from the plant through symbiosis". While the ecological role is not yet clear, preliminary tests suggest that the fungus is neither a

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a g ...

nor an

ectomycorrhizal An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or my ...

symbiont. Prior to the description by Rosling and colleagues, Archaeorhizomycetes was referred to as Soil Clone Group 1 or SCGI after it was originally discovered tundra soils and reported in 2003 by Schadt et al. The taxa were only known from ribosomal

DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. T ...

but it had been found independently in ecological studies of soil in more than fifty cases worldwide using three different gene regions. However, neither fruit bodies nor

spores In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

had been observed. The name ''Archaeorhizomyces'' comes from the Greek ', meaning ''ancient'', which is in reference to the basality of the fungus, ', in reference to roots, and ', in reference to fungi. ''

Archaeorhizomyces finlayi ''Archaeorhizomyces finlayi'' is a species of fungi in the class Archaeorhizomycetes and the type species. When the class was described in 2011, a single order, Archaeorhizomycetales, family, Archaeorhizomycetaceae, genus, ''Archaeorhizomyces'' a ...

'', (named in honour of Roger D. Finlay) was the first species described. It is known from Scandinavia and North America. A second species ''

Archaeorhizomyces borealis Archaeorhizomycetes is a class (biology), class of Fungus, fungi in the subdivision (botany), subdivision Taphrinomycotina of the Ascomycota. So far, the class has only one described order (biology), order, Archaeorhizomycetales, family (biology) ...

'' was described in 2014 together with an estimate that the class may consist of close to 500 species based on sequences available in public databases.

References

{{Taxonbar, from=Q15634529 Ascomycota Taxa described in 2011 Fungi of Europe Fungi of North America Fungus classes Monotypic fungus taxa