Fungus

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Fungus The Latin word for mushroom is fungus (plural, fungi). The word fungus has come to stand for a whole group of simple plants that contain no chlorophyll and lack such complex plant structures as roots, stems, leaves, and flowers. Included among the fungi, along with mushrooms, are molds, mildews, rusts, smuts, truffles, and yeasts. Toadstool is another name for mushroom. Some people use the name toadstool only when referring to poisonous mushrooms, but botanists make no such distinction. A general scientific term for fungi is mycota, from the Greek word for mushroom, mykes, and the study of these organisms is called mycology. Because they lack chlorophyll, fungi are unable to manufacture food out of the raw materials around them as other plants do. They must therefore get nutrition from other plants and from animals. When they get their food from living plants or animals, fungi are called parasites. When they get it from dead plant or animal matter, they are called saprophytes. Fungi are very widely distributed throughout the world, particularly in the temperate and tropical regions where there is sufficient moisture for them to grow. They are less likely to be found in dry areas. Some few types of fungi have been reported in Arctic and Antarctic areas (some molds, after all, thrive on refrigerated food). There are about 50,000 known species of fungus. Although any single typical fungus may not be uniform in appearance--a mushroom, for example, has a cap, stem, and rootlike components--it has, in fact, a uniform structure throughout. The typical fungus consists of a mass of tubular, branched filaments, or strands, called hyphae (singular, hypha). The mass of hyphae is called the mycelium, and it is this that makes up the thallus, or body, of the fungus. In order to grow, the mycelium uses the organic matter, either living or dead, in its environment. As the mycelium matures, it forms spores. These are seedlike reproductive bodies, each normally consisting of one cell, that become detached from the parent fungus and start new organisms. As the spore grows, it develops into a hypha that branches out and eventually forms the mycelium of a new fungus. In some fungi the spores may be produced directly by any portion of the mycelium; in others, such as the mushroom, they are formed in a special fruiting section, such as the mushroom cap. This section,... ... middle of paper ... ...h century was the destruction of elm trees in Europe and the United States by Dutch elm disease. The fungus responsible, Ceratocystis ulmi, probably arrived in Europe from Asia about the time of World War I. By the 1930s it had spread throughout Europe and Great Britain and killed thousands of trees. It appeared in the United States in 1930 and has since destroyed millions of elm trees. Overland spread of the disease normally occurs through transmission by elm bark beetles. One serious fungus-caused disease that may attack people and animals is ergotism. The fungus ergot develops on grasses, especially on rye. It contains a number of poisons called alkaloids. If the grain is harvested and the ergot is not removed, it will get into bread made from the rye and cause ergotism--also known as St. Anthony's fire--for which there is no known cure. The disease may also infect cattle that eat the rye grains left in a field. Ergot also contains lysergic acid, the principle active agent in the drug LSD (lysergic acid diethylamide). The fungus does have some positive uses however. It has been used to develop medicines that induce labor in pregnant women and curtail hemorrhaging after birth.
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