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MUSHROOM IDENTIFICATION

Caesar's MushroomThe best way to learn mushrooms is to have a local expert teach you. Most of us don't have that option, however, so another option is purchase one or more field guides such as those featured at the right and here. You can review some  books on mushrooms in general here.

If you have an idea what genus the mushroom belongs to, you can use a search engine's image-search feature, searching on the genus name as the key word. Also note the mushroom-identifying websites listed in the "On the Web" sidebar below.

How Do Mushrooms Differ from One Another?

Mushroom ringOn the mushroom at the left notice that the stem bears a ring, also known as the annulus. Most mushrooms don't have rings but some do. The presence or absence of a ring is one of the first things you need to notice when identifying mushrooms.

The same is true about the  cuplike affairs known as cups, or volvas, which the mushroom at the top, right arises from. See the white, cuplike thing at the mushroom stalk's base? Often you need to brush away leaves in order to be sure your mushroom does or does not arise from a cup.

The mushroom at the top, right possesses both a ring and a cup. Whenever you find a mushroom with both of these features, beware, because these are features of the main group of deadly poisonous mushrooms, members of the genus Amanita. Not all Amanitas are poisonous (the one in the picture is edible), but a few bites of some of them can kill you... Never eat any mushroom with both a ring and a cup unless you know exactly what you're doing! If you're thinking of eating mushrooms, check out my Eating Mushrooms Page.

Sometimes the mushroom's stalk, instead of arising at the center of the cap, as do in all of the mushrooms pictured above, attaches to the side of the cap.

Boletus, species staining blue, rusty-red cap, under hardwoods in MississippiMany mushrooms, such as the Boletus shown at the left, instead of having gills radiating from the central stalk, have roundish holes, or  pores.

And of course one of the most agreeable things about mushrooms is that they come in a rainbow of colors.

In other words, when identifying mushrooms there are many, many unique and interesting features to use as field marks. Any good mushroom field guide will present a brief survey of mushroom parts, with drawings showing how the parts can vary, and what the various configurations and states are called. Once you begin identifying mushrooms, you enter a whole new world...

ON THE WEB

MycoKey from Denmark, an online identification key that display a mushroom that changes to look like the one you're IDing as you work through the key. The key is for northern Europe, but many of the same genera are found in North America.

Michael Kuo's Key to Major Groups of Mushrooms at MushroomExpert.com

David Fischer's Mushrooms of Lawn, Garden & Home at AmericanMushrooms.com

Mushrooms of California: site describes over 435 species and includes over 1800 photos

Western Montana Mycological Association: offering a simple key

The Boletes of California: Genus Boletus (pores, not gills)

U.C. Berkley's CalPhotos fungus photo database; click on scientific name, see picture

Is Mushroom Identification Easy?

The problem is that there are just so many mushroom species that no easy-to-use field guide can cover them all. The problem is compounded by the fact that mushroom spores can travel for hundreds, even thousands, of miles on wind currents, so any truly comprehensive mushroom field guide would have to include species usually found only far away. When I find a new mushroom, my picture-filled field guide called Mushrooms of North America, by Orson Miller, Jr., despite its impressive name, provides an identification in which I have confidence much less than half the time.

In mushroom identification there's one particularly interesting technique worth giving special mention to. It relates to the fact that different mushroom species produce different-colored spores! Some species produce white ones, others black, brown, rusty, smoky-gray, salmon, pink, or even yellowish or green spores! Spore color is invaluable in mushroom identification.

typical spore print showing white sporesUnfortunately, usually you can't just sit down next to a mushroom and immediately determine its spore color. Usually you must remove the cap, take it home, and place it on a small sheet of clear glass or paper. Ideally, the paper should have both black and white surface areas so that if the spores are white they'll show up on the black part, if black, on the white.

After a few hours, if you're lucky, a beautiful spore print such as that at the left will result. The lines coincide with the gills beneath the cap, from which the spores have fallen. Notice the absence of spores in the very center, where the mushroom's stalk was attached. The spore-print-making process slows down mushroom identification but, once you've done it, it adds to your confidence in the identification... and you have a work of art! By the way, the best mushrooms for making spore prints are those about three-quarters grown. Sometimes the largest, most mature mushrooms in a group have already dropped their spores, while the smaller mushrooms are too young to be producing them.

In case you're thinking of eating the mushroom you're trying to identify, to encourage yourself to do a good job identifying it, you might benefit from reading a report in one of my Newsletters entitled "Poisoned by A Chlorophyllum Mushroom."

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