A few years ago, while teaching at the Edible Schoolyard in Berkeley, I was inspired by the work of Paul Stamets, a mycologist from Washington State whose research has shown, among other miraculous findings, that “fungi can save the world” – they can clean up oil spills and toxic waste, accelerate the regeneration of forests after clear-cutting, control invasive insects, even cure and prevent disease!
As I researched this topic, it became clear to me that the children who are inheriting our world need to know about all of the potential biological solutions for solving the mess that we have created.
Anyone who is learning about fungi needs to first understand a few basic concepts.
First, what is a mushroom?
A mushroom is the reproductive organ of a fungus. In general, mushrooms only appear when a fungus needs to re-locate itself by releasing spores into the air. Normally, this happens when the fungus runs out of food in its local environment.
Fun fact: Fungi are more closely related to animals than they are to plants, as they have digestive systems. They use enzymes released into their local environment to break down foods and then they suck up the nutrients through their cell walls This process is not too far from what happens in our own stomachs!
Which mushrooms are edible?
Most mushrooms are not edible, in fact many are VERY POISONOUS! The safest mushrooms to eat are ones that you buy at a restaurant or market. If you are interested in gathering wild mushrooms, exercise EXTREME caution, making sure to be in the presence of an expert before you bring anything home to eat. Every year people die in the US from eating misidentified mushrooms.
Third, there are two main groups of fungi. They are called saprophytic and mycorrhizal fungi.
Think of saprophytic fungi as decomposers that break down organic matter – leaves, wood, etc. down into the basic building blocks of soil. All cultivated species – the ones you normally find in the store – like Portabella, Shiitake, Cremini, Oyster (shown above) and “Button” mushrooms are saprophytic because they can be grown in a controlled indoor environment in compost piles that they feed upon. Once their mycelium (single-cell chains of root-like fungus) grows throughout the material they are introduced to, they run out of food and shoot out mushrooms, releasing spores that will travel through the air to find another place to grow.
Mycorrhizal fungi can be thought of as “tree companions.” These fungi form partnerships with specific tree species, fusing their mycelium with the roots of the companion tree underground. Sugars the trees produce through photosynthesis are traded for nutrients found in the root zone across this cell-to-cell border. The plant sugars spur the fungus to grow its network wider and wider around the trees roots, providing many times the nutrients a tree could gather on its own. Mycologists believe that most species of plants have a partner fungus. Examples of edible mycorrhizal species include the prized Chanterelle (shown above) and Porcini mushrooms, which form partnerships with Oak Trees and Pine trees, respectively. They are especially valuable because they cannot be cultivated commercially and must be wild-harvested when the conditions are just right.
Interested in learning more?
Try out the Edible Schoolyard’s Mushroom Lesson with your students!
Read more under “Soil Life and Fertility Management” on our Resources page.