Mycology is the study of fungi. Fungi aren't plants, and aren't really animals. They serve a key role in decomposition. Mushrooms are the fleshy, spore-bearing fruiting body of a fungus. Yeasts and slime molds are also fungi.
The Mad Scientists of Etsy monthly challenge was themed "mycology." For my entry I carved three stamps of mushrooms, which are available for purchase at my Etsy shop. I wanted three mushrooms that were different in shape. The button mushroom, which I love to eat, a morel, which I love to hunt, and I'm not entirely sure what the thrid one is, but I liked the shape! Ha!