Ectomycorrhizae
fungus forms a sheath around the root, with hyphae emanating through the soil, greatly increasing the surface area
fungus penetrates between cells of the cortex to facilitate nutrient exchange
fungus is almost always a Basidiomycota, although a few are Ascomycota species
Notes:
Ectomycorrhizae for with only a few families of trees in the temperate and boreal regions. These include the Pinaceae (pines, spruces, etc), the Fagaceae (oaks, beech), the Betulaceae (birches), as well as Aurucaria and Nothofagus in the southern hemisphere. There’s several others. WE’re finding ectomycorrhizae in our lab on some other families of plants.