Mushroom Basics

Mushrooms, a type of fungi, differ from other plants in that they lack leaves, chlorophyll, flowers, and roots. Without chlorophyll, they are obliged to draw nutrition from existing organic materials, so they attach themselves to a wide variety of objects such as wood, humus, and even decayed rags, dirty glass, and rusted metal.

Unlike plants that grow from seeds, mushrooms reproduce by single-cell spores. As they develop, the tiny spores sprout minute filaments called mycelia, which commercial growers normally use for propagation purposes. Some mushrooms are cultivated with manure that has been fermented and pasteurized, or on synthetic manure made from hay, straw, bark, gypsum, or potassium.

The Egyptian pharaohs considered mushrooms to be a food of the gods and prohibited the general population from consuming them. The Romans believed that the fleshy fungi gave people strength and included mushrooms in their soldiers’ diet. At the same time, poisonous varieties of mushrooms have been one of the preferred tools of assassins, as the cause of the victim’s death is often hard to identify. In 54 CE, the emperor Claudius died after eating mushrooms fed to him by his wife Agrippina; Pope Clement VII met a similar fate in 1534; and Holy Roman Emperor Charles VI died after being fed poisonous mushrooms in 1740. Mushrooms have also been associated with witchcraft, which adds to the aura of fear and distrust that surrounds them.

Though mushrooms have a reputation for causing illness or death, only about 1–2% of the thousands of mushroom species are actually poisonous. On the other hand, many varieties do cause health problems such as diarrhea, stomachaches, and vomiting. Various types of mushrooms and other fungi also have hallucinogenic effects if consumed. Strictly avoid eating mushrooms with which you’re unfamiliar. For more on specific types of mushrooms best suited for cooking and eating, see Types of Mushrooms.