Early Paleozoic fossil rhizomes and spores, DNA data and their ubiquitous associations with plants show the Glomales are ancient fungi. VAM probably evolved from endophytes in early bryophyte-like land plants. Most mycorrhizas are balanced with dependant, specialised root-soil fungi and plants adapted to balance association costs with nutrient requirements. Further evolution can result in achlorophyllous myco-heterotrophic plants that exploit fungi for energy and nutrition, but are uncommon due to habitat specificity. Mycorrhizal fungi can also be endophytes, necrotrophs and antagonists.
Most land plants have mycorrhizas and endophytes.
Most ferns, horsetails and club mosses have VAM, but some have facultative VAM or orchid-like associations. Efficient nutrient capture is a major driving force in plant evolution. New root types evolved with plant lineages and are consistent in most families. Roots evolved from rhizomes with VAM to supply water and nutrients to support leaves and complex branching. NM roots are thinner, more branched, active, with more hairs and typically have more advanced chemical defences than mycorrhizal roots.