What is the classification of a button mushroom?

The honey mushroom is part of an organism known as the honey fungus, which is a genus of parasitic fungi known as Armillaria. The mushroom is just the outward manifestation of this very fascinating and somewhat terrifying genus. How might a parasite of trees and shrubs be terrifying? The largest living organism is an Armillaria (sp Armillaria ostoyae). It is thousands of years old and covers about three and a half square miles, much of which is underground. Please understand this is a single organism, one with many metaphorical offshoots and tributaries, but one living thing. I believe it currently resides in Oregon but, given enough time, it could conceivably cover the entire planet. And most people think the largest living organism is the blue whale. The honey mushrooms which emanate from it are not one might think of as individual fungal entities but are, instead, its fruiting bodies, the mode and mechanism of Armillaria reproduction. You will find yourself fascinated if you undertake further research.