Shiny Cinnamon Polypore 
Shiny mottlegill 
Shrubby Cup Lichen 
Silky Pinkgill 
Silky sheath 
Silver leaf 
Silvery Violet Cort 
Singerocybe adirondackensis 
Skullcap dapperling 
Slate Bolete 
Slate grey saddle 
Slender Club 
Slender Parasol 
Slender Psathyrella 
Slimy Milkcap 
Slimy spike-cap 
Slippery jack 
Slippery Jill 
Small Dung Button 
Small Funnel-Veil Amanita 
Small Moss Oysterling 
Smoked Oysterling 
Smokey-eyed Boulder Lichen 
Smoky clavaria