Marasmius capillaris 
Marasmius crinis-equi 
Marasmius lachnophyllus 
Marasmius plicatulus 
Marasmius purpureostriatus 
Marasmius strictipes 
Marasmius sullivantii 
Marsh Webcap 
Marshmallow bolete 
Marshmallow Polypore 
Massospora cicadina 
Matte Jack 
Mauve Bonnet 
Mauve Elfcup 
Mauve Splitting Waxcap 
Mayapple Rust 
Meadow Mushroom 
Meadow Puffball 
Meadow waxcap 
Mealy amanita 
Mealy Forked Lichen 
Mealy Pixie Cup 
Megacollybia subfurfuracea 
Melanelixia fuliginosa