An
ectomycorrhiza (Gk. ἐκτός,
ektos, "outside;" μυκός,
mykós, "fungus;" ριζα,
riza, "roots;" pl.
ectomycorrhizas or
ectomycorrhizae, abbreviated EcM) is a form of
symbiotic relationship that occurs between a
fungal symbiont and the
roots of various
plant species. The
mycobiont tends to be predominantly from the
phyla Basidiomycota and
Ascomycota, although a few are represented in the phylum
Zygomycota. Ectomycorrhizas form between fungi and the roots of around 2% of plant species. These tend to be composed of
woody plants, including species from the
birch,
dipterocarp,
myrtle,
beech,
willow,
pine and
rose families.
