Have you ever walked past a mushroom and thought to yourself, “I wonder if I could eat that”? I recommend that you do not. That said, there are many of experienced mushroom foragers out there who are extremely experienced and capable of identifying edible mushrooms. Foraging is a skill that, like all skills, is developed over time and through repetition. Skillful mycologists, weather permitting, never have to shop to put food on the table. Between the exercise and the edibles, foraging can be a fun and efficient way to eat.
Identifying mushrooms can be very difficult. The smell, look, and feel of a mushroom growing out of a log can indicate its species, but usually you need to know a lot more. Generally, the insides are what matter. The size, shape, and spacing of the gills (the frilly bits under the cap) can be a huge indicator. The shape of the stipe (the stem-like bit jutting out from beneath the cap) and the direction of its taper can also yield useful information.
There are also many microscopic features of a fungus that can help to identify it. While a microscope can be helpful, it isn’t always necessary to determine the species. Many mycologists use a method known as “spore-printing” to determine mushroom type. To do this, they simply cut off the stipe and place the mature mushroom gills-down on a piece of white paper. To prevent the spores from being moved by air currents, one should also place a bowl over the mushroom. Typically one need only let it set overnight to get a good spore print. When you remove the bowl and lif the mushroom cap, you’ll notice a pattern of spores which usually reflects the pattern of its gills. The color of the spores aids tremendously in the identification of the mushroom.
The location of the mushroom is also an important feature. One obvious factor is geographic location; there are different mushrooms in different climates. The material the mushroom grows in is also important. The material is known as the substrate. Certain mushrooms only grown on certain substrates, thus being able to identify the flora in the region can help identify the mushroom type. A mushroom can grow in leaves, other fungus, out of tree trunks, or in dung. Clearly, some mushrooms are more appetizing than others.
If you’re new to foraging and identifying mushrooms, it is never a good idea to eat anything you find unless you are with someone who knows what he or she is doing. If you choose to do so in spite of your better judgment, always leave a sample of the mushroom that you ate on a note near your phone (which, ideally, you used to call poison control right after ingestion). This way the paramedics will have an easier time diagnosing and treating you afterward.
There are several ways to learn more. Ideally, you could take a class. The Fungus Federation of Santa Cruz offers classes on mushroom identification. Additionally, the UC Santa Cruz Office of Physical Education and Sports offers several classes per quarter. For additional material, there are several useful field guides with useful illustrations in several local bookstores. Guidebooks are handy, since they have keys that act as an identification flowchart. However, a field guide is not a good substitute for a class, so check one out while it’s still wet out!