Red Dock Spot 
Red Edge Brittlestem 
Red Hot Milk Cap 
Red ring rot 
Red Stinkhorn Fungus 
Red-banded Cortinarius 
Red-belted Polypore 
Red-ring Rot 
Red-stipe bolete 
Reddening Lepiota 
Reddish brown bitter bolete 
Redlead Roundhead 
Redleg toughshank 
Reindeer Lichen 
Reindeer Lichen 
Resinomycena rhododendri 
Resinous Polypore 
Resupinatus alboniger 
Rhizocarpon geographicum 
Rhizoplaca chrysoleuca 
Rhizopogon occidentalis 
Rhizoporus oligosporus 
Rhizopus arrhizus 
Rhodophana nitellina