Hymenochaete cruenta 
Hyphodontia arguta 
Hypholoma dispersum 
Imleria pallida 
Inocutis dryophila 
Inocybe fuscodisca 
Inocybe lacera 
Inocybe mixtilis 
Inocybe subochracea 
Inocybe tahquamenonensis 
Inocybe xanthomelas 
Inonotus obliquus 
Inonotus quercustris 
Inosperma subrubescens 
Insidious Gomphidius 
Iodine bolete 
Irpex lacteus 
Ivory bonnet 
Ivory waxy cap 
Jack O' Lantern Mushroom 
Jewelled Amanita 
King Stropharia 
King Trumpet Mushroom 
Kuehneromyces marginellus