Mushroom Every so often I get an email asking me if the thing in the attached photo is a mushroom or a toadstool. I want to say: What the fuck does that even mean? But I don't. I just click "delete" and move on with my life. "Mushroom" isn't a scientific term. I once had a very good teacher who defined poetry as "any text someone asks you to consider as poetry." I'm inclined to do more or less the same with "mushrooms." They are fungi, but they are definitely not all fungi (a category that would include, for example, ring worm and the bluish mold that appears on your bread)—so where you want to draw the "mushroom" line within the fungi is up to you. That said, one good way of understanding mushrooms, I think, is to consider them as spore factories. Most of the time, the fungal organism in question spends its time as vegetative mycelium, looking nothing like the "mushroom" thing we're talking about. But when the reproductive urge takes hold (that's called "personification"), the fungus produces a spore factory—a structure to make babies and send them out into the world. Perhaps the organism designs a stem or a pseudostem, preparing to lift the spore-producing shop floor high enough so that the spores will easily catch air currents. Perhaps a cup is created, or a cap, to hold the floor. Asci or basidia, the actual spore-producing machines, are erected all across the floor. Some organisms increase the factory capacity immensely by increasing the floor size with gills, false gills, or tubes. Sometimes the factory adds safety features: veils are erected to cover and protect the machinery until the spores are ready. As soon as the spores are released, the factory shuts down. The "mushroom" wilts, decays, and eventually disappears. But the organism itself continues, perhaps in the same place, if the mycelium has not run out of nutrients—or somewhere else, when spores land in just the right places, germinate, and develop into mycelia. Pictured to the left is probably the most iconic "mushroom" in the world, Amanita muscaria var. muscaria. The Mario Kart mushroom. The old-farm-woman-bending-over-in-her-polka-dotted-dress mushroom. The hookah-smoking-caterpillar-Lewis-Carroll mushroom. Amanita muscaria is one of the more complex and elaborate (and beautiful!) spore factories; it features a long stem, a universal veil to protect the construction of the factory, a partial veil to protect the spore-producing machinery, and the perfect timing required to raise the cap up and expand it to break the veils and release spores.