A Cook's Mushroom Miscellaney

What is a Mushroom?

The mushroom we see and eat is a part of the reproductive structure of a plant we know as a "fungus." The sole purpose of this organ is to manufacture and spread spores to reproduce its species. The part of the plant we don't usually see, the threadlike mycelium living in soil, wood, animal, or plant tissues, constitutes the vegetative portion of the plant. This is the structure of the organism that takes nourishment from living or dead organic material and the earth around it.

Most of the tissues of a fungus are composed of mycelium that forms the parts seen with the naked eye. The mycelium draws its basic food material from the place where it grows. Lacking chlorophyll, which makes the leaves of most plants green, the fungus is unable to manufacture sugar, the backbone for the chemicals needed for life. Carbohydrates such as sugar must be derived from the tissues of other organisms. Acids, iron, calcium, and other inorganic materials are derived from the soil, wood, or animal substances in which the mycelia grow.

Some mushrooms are parasitic, such as the oak-tree fungus, Armillaria mellea (honey mushroom). Others digest dead tissues from plants and animals. We call these saprophytes. A more complicated relationship exists between the root hairs of vascular plants such as trees, which become coated with mantles of mycelia. Such mycorrhizal (fungus-root) interminglings improve a tree's vigor and nourish the mushroom as the tree and the fungus exchange nutrients essential for their lives.

What about the food value of mushrooms? Ninety percent of their weight is water. They are low in calories, but high in roughage. Some yellow and orange mushrooms, such as chanterelles, provide Vitamin A in the form of carotene. B vitamins are present, but not Vitamin C. Not much fat or carbohydrate is found. Mushrooms do not form starches. They do contain minerals such as potassium and magnesium, but not much sodium.

In Asia, fungi have been intensely studied in the hope that their use can supplement dietary protein. Experiments have demonstrated that the maximum protein content and the best amino acid balance are found in mushrooms just before the caps expand. We must conclude that the major food value of mushrooms lies in their protein component.

The walls of the mycelium, which make up the solid substance of the mushroom, are composed of chitin, the substance forming the exoskeleton of insects. Humans do not have the necessary enzymes to digest this material. Cooking breaks down the mycelial walls, releasing the nutritious components of the fungus available for assimilation as food.

Mushrooms As Medicine

In China, mushrooms are valued as much for their healthful properties as for their taste and texture. The Chinese incorporate a wide variety of fungi into their diet for specific medical purposes as well as for general good health. Chinese doctors have been using fungi medicinally for twenty-five hundred years, calling them the "fruit of the earth."

The Chinese do not consider their medicine to be simply folk medicine. Their medical practice is well organized, amply recorded, and long on observation and experience.

In China, the properties of mushrooms have been codified for medical usage. For complete physical and mental health, one ideally balances the yin and yang elements. The yin contains negative qualities and the yang positive ones. Using foods to which these elements are traditionally attributed, herbal practitioners construct a dietary program to correct imbalances thought to be causing an illness. Mushrooms are generally in the yin group.

Among the fungi used in Chinese medicine are the shiitake, ear, snow, oyster, and monkey head mushrooms discussed in this book.

Home Mushroom Cultivation

The hunting of wild mushrooms is so popular that in certain areas in the United States and Europe choice edibles like the chanterelle (Cantharellus cibarius) and Boletus edulis (cèpe or porcini) are becoming scarce. It's no surprise that some mushroom fancier s are considering mushroom cultivation as an alternative to long treks in the woods. Cultivation offers several advantages over field collection: it provides mushrooms all year round rather than just during the rainy season; the specimens are low in cost and insect free; poison oak and ticks are avoided; and there is freedom from the suspicion unique to mushroom hunters that a favorite collecting patch has been violated by others.

Growing wild mushrooms would seem to be a simple matter: properly duplicate the conditions under which mushrooms grow in the wild, and success should follow. In practice, however, cultivation using the most carefully controlled techniques can be challenging, and crop failures are not unusual. Still, amateurs employing primitive methods sometimes realize excellent results. An example of a simple cultivation project could involve transplanting a piece of sod containing the fairy-ring mushroom, Marasmius oreades, from one lawn to another, or using a piece of wood from a tree harboring oyster mushrooms, Pleurotus ostreatus, to innoculate a hardwood log. With time and luck, mushrooms might appear.

But just as likely, competing organisms and improper conditions might interfere with the experiment, yielding poor results. To produce mushrooms, growers use pure cultures and composts, and temperatures and moisture levels are carefully tailored to the needs of each particular mushroom.

At this time, there are about a dozen kinds of mushrooms that can be fairly easily grown. Seven are mentioned here. At the head of the list is the familiar common store mushroom, Agaricus bisporus, and its cousin, A. bitorquis. Both are usually grown on composted horse manure. Interestingly, the same growth material is also used to cultivate the shaggy mane, or inky cap (Coprinus comatus). The easiest of the wild mushrooms to grow is Pleurotus ostreatus, the oyster mushroom, which can be brought to fruit in less than three weeks. Shiitakes (Lentinus edodes) and enokis (Flammulina velutipes) are similar to the oyster mushroom in that they grow on wood. They can be cultivated on oak and alder logs, but in California they are typically grown on sterilized logs made of hardwood sawdust and rice bran. Finally, the attractive purple mushroom known as the blewit (Clitocybe nuda) can be cultivated outdoors in beds of oak leaf mold, although it often takes a year before the mushroom caps emerge.

Alas, the cèpe and the chanterelle are not found on this list. They are part of a large group of choice mushrooms that cannot yet be grown commercially. These mushrooms live in association with the roots of specific trees, making it difficult to determine and control their growth requirements. But the future holds much promise for these very desirable delicacies. Because of their potential economic value they are the subject of active study, and it is possible that their cultivation will be successfully worked out, perhaps by growing them in plantations with host trees.

Mushroom Manners

Mushroom hunting is a highly rewarding hobby. Not only does it get us out into the countryside and expose us to the beauty of nature, but it can often provide a delicious dish for dinner. It is amazing how fast problems fade into the background when a group of beautiful or unusual mushrooms are discovered in the woods. We are fortunate in the United States to have rich, abundant, and varied forests that promote the growth of many different kinds of mushrooms. In an effort to ensure that our forests continue to exist and that we live to enjoy them, here are a few simple guidelines with respect to mushroom collecting.

Everyone is aware that often there are poisonous mushrooms growing among the edible ones, yet one or more people are poisoned every year, mostly as a result of carelessness. Remember this: the fact that you might have collected and eaten mushrooms from the same spot for the last twenty years does not in any way preclude the appearance of poisonous varieties in that area at any time. Do not eat any mushroom unless you are absolutely positive of its identity.

Here are a few additional suggestions. Respect private property. Don't destroy fences or damage plants. We don't want to foster the appearance of more signs reading "Mushroom Hunters Keep Out!" Be judicious in collecting. Keep your fellow hunters in mind. They too would like some chanterelles for dinner. Disturb the soil as little as possible.

Remember that nothing is gained from knocking over mushrooms that don't interest you. Leave them alone. Who knows, there might be someone behind you who is interested in identifying or photographing them. Lastly, please don't contribute to the increasing amount of litter discarded in our forest and waysides. We have all stumbled onto mushroom "kitchen-middens," places where a collector has discarded undesirable mushrooms or trimmed off diseased pieces that look most unattractive and unnatural in the woods or on the roads. These discards persist for a surprisingly long time and often are repulsive in appearance. If you sort and clean your mushrooms before returning home, please don't do it along trails or roadsides where the discards are readily visible. If possible, bury the debris or toss it into the garbage.

These suggestions are meant to add to the safety and pleasure of mushroom hunting, and to help you enjoy a good meal of wild mushrooms. Keep it up! Enjoy it to the fullest! Just keep your fellow collector in mind and help him to enjoy them as much as you do. Good hunting!

--Dr. Harry Thiers