Simplify the following text for a Grade 10 native English-speaking person.
Original: A mycorrhiza ( Gk . , : fungus roots , pl mycorrhizae , mycorrhizas ) is a symbiotic ( generally mutualistic , but occasionally weakly pathogenic ) association between a fungus and the roots of a vascular plant .
Simplified: A mycorrhiza ( Greek for fungus roots ) is a symbiotic association between a fungus and the roots of a plant .