Here Comes the "Fun Guy": The Mushroom

From November, 2009 Newsletter

By Esperanza Sanz Escudero, Intern


Many good and devilish things have been said about the mushroom.  There are countless species coming in every shape, size, and color in nature. Everyone has an opinion about them. You love them or you just hate them. During fall, there are many exhibitions all over the world (Asian and European culture use them heavily in their cuisines). Do you want to learn more about them?

Pictures: Agaricus on Middlefield Road in Mountain View, Oct 14th, 2009, and some mushrooms on a log in Jasper Ridge BP, Oct 15th, 2009. Just a few days after the big storm happened.

With the summer being over and the rainy season just started, and old friend comes to visit our lawns and forests: the mushroom. They are all over. They even appear in the last place you might think on Earth... Antarctica! The "mushroom" is in all of our planet's ecosystems.

Scientist studying them are called Mycologist, that comes from the Greek word myco meaning fungus. In addition to the most "famous" fungi, the mushroom, this group includes molds, rusts, mildews and yeasts. There are around 70,000 species of known fungi, but experts say that probably the number is much larger.

Science of mushroom is so interesting. Even today there is still some controversy over whether they are closer to plants or animals. Once they were classified as plants but nowadays they have their own kingdom (Fungi). They are neither plants, nor animals, but believe it or not they are actually closer to animals than plants.  One of the main discoveries was that fungi have a cell wall structure similar to plants, but instead of cellulose, they are built with something called chitin, a protein normally found in the outer skeleton of insects, crabs, shrimps, lobsters and in other invertebrates.

They do not produce their own food (they don't have chlorophyll); instead they get their nourishment from organic matter (animals or plants).  Fungi are decomposers. They reproduce through something called spores, that they drop from their gills to the ground and then produce mycelia the same way as seeds for plants sprout.

There are two major groups that are distinguished depending on where the spores are formed. The most common and also the most evolved mushrooms belong to the basidiomycetes group  (like agarics, boletes, chantarelles and many others). In those, 8 spores are formed in a structure called basidium. When spores are formed in a structure called ascus (like truffles, morels and others), the group is called ascomycetes. The number of spores formed in those are 4. The most colorful, big, edible and poisonous mushrooms belong to the first group described.

Truth is that we live in a climate where mushrooms grow easily and there are many chances to see them around.  In California, we are able to find many hundreds of mushroom species. Out of them, around 10 are deadly poisonous (even eating only small amounts) and many others could cause different reactions (going from mild to severe, depending on the type of fungus).  Suggestion: do not pick your own mushrooms to eat. Trust the ones at the store. What could look so similar, might give you trouble at the end.


"Field Guide to California" National Audubon Society. 1998

"Science Desk Reference " The New York Public Library. 1995

"Hongos" El Norte de Castilla. 1992

Pictures credits: Ignacio Martin Bragado and Esperanza Sanz Escudero