arbuscular mycorrhiza
An arbuscular mycorrhiza is a type of mycorrhiza in which the symbiont fungus penetrates the cortical cells of the roots of a vascular plant forming arbuscules. Arbuscular mycorrhizas are characterized by the formation of unique structures, arbuscules and vesicles by fungi of the phylum Glomeromycota. - wiki
You see those little white strands hanging off the root of the plant? Those are arbuscular mycorrhizal.