The
ericoid mycorrhiza is a
mutualistic symbiosis formed between members of the plant family
Ericaceae and several lineages of
fungi. The symbiosis represents an important adaptation to acidic and nutrient poor soils that species in the Ericaceae typically inhabit, including
boreal forests,
bogs, and
heathlands. Molecular clock estimates suggest that the symbiosis originated approximately 140 million years ago.