First, keep in mind that Fungi is one of the Kingdoms; it separated from Animalia after they collectively said goodbye to Planta. It's BIG, and it's OLD. Now,

First, keep in mind that Fungi is one of the Kingdoms; it separated from Animalia after they collectively said goodbye to Planta. It's BIG, and it's OLD. Now, keep in mind that 99% of the cell mass of most fungi exists as sheets, globs, or relatively uninteresting white mycelia - tiny meandering threads. Apparently not a lot of differentiation is needed there for their jobs! But for reproduction, a mass of white threads that even mycologists can't identify without DNA equipment can suddenly (in hours to a couple days) sprout a GIGANTIC (0.1-6 inch tall!) fruiting body, that is either white, yellow, orange red, purple, blue, green, brown, gray, or (rarely) black. Or mixes thereof. Sometimes emerging from an egg-shaped wrapper like an Alien(tm); sometimes erecting a lattice structure to speed construction up; sometimes building itself into a ledge a 200-lb human can sit on. It's as if you could take home from the big-box DIY store a small, gray pellet, and when you soaked it in water it would transform overnight into a shed, or house, or driveway, or supporting wall, or French drain, or lit walkway (Oh, yeah: mushrooms can visibly glow!), or stairs... Only thing is, all the pellets are in one giant bin. Yet, despite that huge diversity, there are only about 7 "kinds" of mushroom bodies worldwide, and all non-antarctic continents have all the kinds (mushroom, bag-o-spores, creepy thick hairs, mushroomy but with teeth instead of gills, I forget the rest). The antarctic continent has at least two kinds: Agaricus bisporus (pretty much all the ones you've ever eaten), and another kind generally brought in as spores...