Mycology, Anyone?

I get all my big words from my husband.

Mycology is the study of fungi. To get a close-up of this yellow burst of fungal joy I had to poke my camera under a cyclone fence. I left some of it in the photo for scale, and you can see its shadow manifested in lines on the puffy, yellow, mushroomy, whatever-it-is. You know I googled. All I got was yellow fungus.

Any ideas?