Glomerales is an order of symbiotic fungi within the phylum Glomeromycota

Glomeromycota

Glomeromycota is one of seven currently recognized phyla within the kingdom Fungi, with approximately 230 described species. Members of the Glomeromycota form arbuscular mycorrhizas with the roots or thalli of land plants. Geosiphon pyriformis forms an endocytobiotic association with Nostoc...

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Biology

These Fungi are all biotrophic mutualists. Most employ the arbuscular mycorrhiza

Arbuscular mycorrhiza

An arbuscular mycorrhiza is a type of mycorrhiza in which the fungus penetrates the cortical cells of the roots of a vascular plant....

l method of nutrient exchange with plants. They produce large (.1-.5mm) spores (azygospore

Azygospore

Azygospore is an asexually formed zygospore in fungi.Also known as parthenogenically formed from a gamete without gametic fusion.-References:...

s and chlamydospore

Chlamydospore

A Chlamydospore is the thick-walled big resting spore of several kinds of fungi. It is the life-stage which survives in unfavourable conditions, such as dry or hot seasons....

s) with thousands of nuclei.

Phylogeny

All members of their phylum were once thought to be related to the Endogonaceae, but have been found through molecular sequencing data, to be a closer relation to the Dikarya

Dikarya

Dikarya is a subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota, both of which in general produce dikaryons, may be filamentous or unicellular, but are always without flagella. The Dikarya are most of the so called "higher fungi", but also include many anamorphic species that...

. Their fossil record extends back to the Ordovician

Ordovician

The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...

 period (460 million years ago).

Orthography

The family name Glomeraceae upon which this order level name is based, was incorrectly spelled 'Glomaceae', hence the order name was incorrectly spelled 'Glomales'. Both are correctable errors, to Glomeraceae and Glomerales, as governed by the International Code of Botanical Nomenclature. The incorrect spellings are commonplace in the literature, unfortunately.