This type shows the characters of both ectotrophic as well as endotrophic mycorrhizae. The root affected by such forms show an external mantle of hyphae as seen in ectotrophic forms. Some of the hyphae are penetrate the root cortex intracellularly. This is also characteristic to ectotrophic types. As in the case of endotrophic types, here the mycelium penetrates the host cells and lead an intracellular growth. Thus the mycorrhiza of this type have both the characters of ectotrophic and endotrophic types.
Mycorrhiza play a very significant role in afforestation. Seedling of forest tress can grow well after having the correct and specific mycorrhiza.