Creatures of Symbiosis and Decay

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About
Unlike plants, the fungi have no chlorophyll and cannot harvest energy from sunlight. They therefore live off the substance of other living things, including plants and plant remains. Different mushrooms do this in different ways. Some mushrooms, including boletes and truffles, form a symbiosis with living trees, a relationship in which both partners benefit: the mushrooms gather soil minerals and share them with the tree roots, which in turn share the tree’s sugars with the mushrooms. Some fungi are parasites on living plants and cause disease; we eat the plant parasite that infects corncobs (corn smut, or huitlacoche). And some, including the world’s most popular mushrooms, live off the decaying remains of dead plants. White and brown mushrooms apparently evolved along with plant-eating mammals to take advantage of the animals’ partly digested but nutrient-rich dung! They now thrive in artificial piles of compost and manure.