define mycorrhizae
A mycorrhiza (Greek: Î¼ÏÎºÏÏ, mykÃ³s, fungus, and ÏÎ¯Î¶Î±, riza, root, pl. mycorrhizae or mycorrhizas) is a symbiotic association between a fungus and the roots of a vascular host plant. The term mycorrhiza refers to the role of the fungi in the plants' rhizosphere, its root system. Mycorrhizae play important roles in soil biology and soil chemistry.