Aborted entoloma 
Acarospora fuscata 
Admirable bolete 
Aesculus Leaf Blotch 
Agaricus andrewii 
Agaricus campestris 
Agaricus deardorffensis 
Agaricus moelleri 
Agaricus vinosobrunneofumidus 
Agrocybe erebia 
Agrocybe firma 
Agrocybe pediales 
Agrocybe praecox 
Agrocybe putaminum 
Akanthomyces aranearum 
Alder Scalycap 
Alectoria sarmentosa 
Aleurodiscus disciformis 
Alyxoria varia 
Amanita americitrina 
Amanita ananiceps 
Amanita aprica 
Amanita atkinsoniana 
Amanita augusta