Sunday, 2 December 2012

Nature and Science - The Family of Fungi (

Part 1: Children of the Forests
Part 2: Witch’s Circles
Part 3: Killer or Savior
Part 4: The Temptation of Truffles

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The Family of Fungi (Part 1): Children of the Forests 
09-28-2006 13:47

Ancient Siberians called mushrooms the “children of the forests”, because about 70% of the edible mushrooms are found only in forests. Fungi appeared on the earth four hundred million years ago, and can be found in every corner of the planet. The fungi we often see and call mushrooms are actually only the part that grows outside of the soil, which is called the “fruiting body” by mycologists. Actually the most important part of a fungus is its “mycelium” underground. Though the growth of fungi resembles that of plants, they are actually not plants, because they have no chlorophyll and are incapable of photosynthesis as they don’t use energy from the sun.

Fungi have something in common with insects. For example, stag beetles have a strong crust that supports and protects their bodies. Mushrooms are supported by their caps, gills and stems.

Fungi are neither plants nor animals, and are very delicate, capable of only growing in humid and shadowed places at a rapid rate.

Humans knew of fungi long ago. In 1450 BC, Pharaoh Tuthmosis III built the Karnak Temple to the south of the Grand Pyramid. There were murals on the walls of the temple depicting the pharaoh’s battles in many places and different plants and animals, including mushrooms. These are probably the earliest pictures of mushrooms in history. Some mushrooms were even considered delicacies in ancient times.

This mushroom is called the Caesarian Mushroom and grows in warm oak and chestnut forests. Its cap can grow to a diameter of 20 cm, and was loved by Roman emperors. For this reason, it was named after Julius Caesar. During the reign of the Roman emperors, all Caesarian mushrooms found were meant to be presented to the emperor. Those found eating this mushroom privately could be executed.

After millions of years of evolution, many fungi have learned to adapt to harsh environments. Some of them can even grow under ice and snow.

Golden mushrooms, also known as winter mushrooms, have now become a common mushroom that grows from November to April on deciduous tree trunks and branches, especially willows and white poplars. Their fruiting body is edible.

Fungi can grow under snow as well as above it. Sarcoscypha coccinea begins to grow in March when it is still snowing. The common morel mushroom grows in mixed forests or low lying forests and is a delicacy for mushroom lovers. Its close relative morchella semilibera can be found under tender grass. But people should beware of the brain mushroom that grows in the same period. They grow nearly exclusively in pine forests. The gyri on their caps are their special feature. If you put them into your basket, you might be making a fatal mistake.

Many scientific documents accumulated over hundreds of years are kept in medieval monasteries. In the big library of Convent Admond in Styria, Austria, about 80,000 books were collected over a period of 5 centuries. Starting in the 18th century, a great deal of information was gathered about the feature, shape and growth environment of fungi.

For many centuries, people concentrated their attention on edible fungi. Our ancestors discovered that chanterelles are really delicious. They grow in both deciduous and coniferous forests. Now chanterelles, boletus edulis and umbrella shaped mushrooms are still commonly used by gourmets.

In summer and autumn, light yellow mushrooms are delicacies sought by many people. But both boletus and chanterelle are not artificially cultivated so far. Other than buying them in the market, people can only pick them for themselves in the forest. They have velvet caps and are called summer boletus by experts. They can be picked as early as May.

Summer boletus grow in deciduous forests, especially pure oak forests. Scientists confirmed decades ago that there is a mutual dependence between some fungi and special trees, in both deciduous and coniferous forests. These fungi are symbiotic with particular species of trees, and are thus difficult to cultivated artificially. Boletus edulis is one such example.

The Family of Fungi (Part 2): Witch’s Circles
09-28-2006 13:49

Although the boletus edutis is a delicacy, there is only way to find them and that is by picking them in the forest. Boletus mushrooms grow at the soft roots of trees, and form mycorrhizas within the roots. People have tried hard to cultivate boletus edutis in green houses but to no avail.

Most other varieties of mushrooms and fungus aren’t so particular about where they are grown. Under a suitable temperature they can easily thrive in the special soil found in greenhouses. When the mycelia are planted in a mixture of humus and horse manure, and enough water is sprayed on them, button mushrooms will shoot out within two weeks. After 21 days, button mushrooms are ready for classification, packing and sale. In Germany and Austria alone, about 63,000 tons of artificially cultivated mushrooms are produced every year.

The technology of producing button mushrooms is now no longer a secret. But many other mushrooms are still a mystery. One of the biggest mysteries is how their internal timer works. For example, the common dictyophora grows out of a “witch’s egg”, as though suddenly pushed by an invisible power. The body of the common dictyophora has a strange appearance and can grow to a size of 20 cm in diameter. It smells like rotting flesh and draws a lot of flies.

In the forests, there is a strange mushroom that has 4 to 6 tentacles stretching out of its egg-like cap when it is born. This kind of squid-like dictyophora originally grew in Australia but was introduced into Europe in 1913. It’s frequently seen in Germany now.

When the mycelia of fungi grow evenly in all directions underground, fruiting bodies may shoot out of the soil equidistant from a center and form a circle. These are known as “witch’s circles” .

Fly agarics usually grow in groups and are easily recognized because of their unique appearance. They were known thousands of years ago for their notorious toxicity and details of their effects were recorded in the Middle Age.

Alchemists and wizards extracted mysterious drugs from the venom of fire lizards and snakes. They also used fly agarics as an ingredient in their elixirs. The toxin, muscarine, in fly agarics can produce illusions and is used as a narcotic. But over-dosages are very dangerous. Up until the 19th century, people frequently picked fly agarics for different uses. For example, farmers often used them to kill flies. Small chips of the mushroom mixed with milk will attract large numbers of flies and other insects. They die quickly in large numbers after drinking the mixture.

Unlike fly agarics, coffin web-caps have no unique appearance and are easily mistaken as edible mushrooms. It is now listed as a fatal poisonous mushroom. In 1957, a Polish newspaper published a story about 19 people being killed by coffin web-caps in a short time, due to people mistaking the toxic mushroom for edible ones.

Common ink-caps and glistening ink-caps begin to grow in May, mainly in deciduous forests. Their caps are easily broken and their growth period is short. Experts suggest that they should be picked before they are fully grown. A small amount of these mushrooms will greatly improve the taste of a soup. But if you drink wine at the same time, a toxin will be formed by the interaction of the mushrooms with alcohol, causing blushing, skin specks and puffing. Fortunately, these symptoms are not fatal. Without wine, you can enjoy the delicacy of ink-caps at ease. People can find rare mushrooms even in places like city parks and gardens. For example, in spring, people may sometimes find St. George mushrooms in city parks. Sufficient water sources are the key condition for the growth of the mushrooms. Not only edible mushrooms like St. George’s mushroom grow in city gardens though. Very poisonous ones can also be found, such as the reddish fiber-cap. Reddish fiber-caps are characterized by their broken caps.

If you plan on going mushroom picking, it is always advisable to bring a reference book along, no matter what type of mushroom you are hunting for. If you mistake a reddish fiber-cap as an edible mushroom, you are risking your life. 50 g of that mushroom is enough to kill a person--the toxin is 200 times more toxic than muscarine.

The Family of Fungi (Part 3): Killer or Savior
11-28-2006 16:12

One of the most poisonous mushrooms in the world can be found in the forests of Austria. Not surprisingly, it is called the death cap. Even worse, the shape and color of death caps change constantly. However, they are still recognizable through the following features: a sack-like white volva at the base, a white membranous ring shielding the white gills, a white spore print and the smooth rather than lined cap margin. It grows in deciduous as well as coniferous forests. Because of its changeable appearance, it is often mistaken for other mushrooms, such as the honey mushroom and paddy straw mushroom, both of which are edible. As a rule of thumb, you should never pick any mushroom with a bulb or sack-like volva at the base, unless you are absolutely sure of what you are picking.

Eleven grams of death cap mushroom can kill an adult. Its toxins exist in every part of the fungus and it is also very difficult to dispose of, as the toxins will not decompose even if boiled, frozen or dried. Any dish containing even minute amounts of death cap mushroom poses a serious danger.

To make matters even worse, symptoms as a result of eating a death cap mushroom will not show up until 8 to 10 hours after eating. The initial symptoms are nausea, vomiting and diarrhea. Treatment should be immediate at this stage. When the liver is seriously damaged, it’s too late. 90% of mushroom poisoning cases are due to death caps. Moreover, slugs can eat any part of the mushroom without being poisoned so if someone follows the example of slugs, he or she is running a fatal risk.

Slugs are invertebrate gastropods. They are immune to nearly all mushroom toxins, and can eat any highly toxic mushroom, including reddish fiber-caps. In-depth professional knowledge and personal experiences are needed to avoid mushroom poisoning. Distinguishing toxic mushrooms from edible ones is very difficult using just the naked eye.

Fungi germinate from tiny spores with a diameter of 0.01 mm. They are easily ejected by vibrations and grow rapidly in a suitable environment. A ripe fungus contains billions of spores. Some spores, like mould spores for example, grow easily on food.

If you expose a loaf of bread to air for 4 weeks, it will be covered in mould like this. Moldy food is not edible and is sometimes poisonous. But some fungi are even beneficial to humans. In 1928, Alexander Fleming, a Scottish bacteriologist was studying influenza and pneumonia. That summer, he left his lab to have a holiday, but forgot to put a culture dish that contained a culture medium with bacteria into the fridge. By accident, a fungal spore found its way into the dish and began to germinate and grow.

The fungus ended up killing all the pathogenic bacteria around it. A few weeks later, Fleming came back and soon realized what the accident had brought on. The first highly efficient antibiotic in the world was thus discovered and named penicillin, which has saved many lives and is still in use today. It evoked a revolution in the field of medical science and Fleming won the Nobel Prize in 1945 for his great contribution.

Not only humans are benefited by fungi. Many species living in tropical rain forests also have a special relationship with fungi. Most of them are still unknown to us.

Mycologists believe only about 30% of tropical species are known to us so far. Among the vast number of strange species in forests, there is a species called myxo-bacterium. Myxo-bacteria have several stages in their life and move in a strange way. They live on rotten wood and leaves, eating different bacteria as they grow and move. They have no tissues and form vein-like networks that stretch and shrink regularly. When the temperature or humidity are not ideal, they can contract to form a lump. Bacteriologists are still unable to describe many of these strange living creatures.

Leaf-cutting ants are also residents of tropical rain forests. For millions of years, they have been developing their technology of fungi cultivation. Thousands of worker ants keep themselves busy carrying leaf pieces they have cut from plants. These pieces are put into countless labyrinth-like tunnels and are used as fungi cultivating bases. Fungi grow on them and cover the ants’ residence with a cotton-like material. These materials serve both as food and construction materials for the ants.

The Family of Fungi (Part 4): The Temptation of Truffles
11-28-2006 16:34

For hundreds of years, truffles have been sought as a rare delicacy at a high price. They are often regarded as the “caviar” of fungi. They only grow underground in forests, and can only be tracked down by certain animals. In Italy and France, tamed pigs are used to locate truffles. The dark blocks which countryside people ate in the past are now luxurious food for international VIPs.

Even today, the methods used in finding truffles in forests of oak, white poplar, hazel or beech are unchanged after hundreds of years. Truffle hunters must have patience and know how to control their pigs, as pigs are clever and omnivorous. Pig trainers must also make sure to check them in time or they will eat all the truffles. The quality and size of truffles vary with the species and place of origin, and will be evaluated after picking.

Autumn is the traditional season for hunting for truffles. Soon after sunrise, many quiet households begin to get busy. Dogs are ready to begin the day’s work. This dog is well trained for seeking truffles, and is an indispensable assistant for his master, a professional truffle picker in Burgundy. The first thing they do every morning is head into the forests. There is no need to persuade the dog, because it shares the happiness of finding a truffle with its master.

In Burgundy and other truffle production bases in the Mediterranean area, the practice of seeking truffles with pigs is decreasing and more and more dogs are being employed, as they are faster and have a keener sense of smell. They are trained in special schools or by their masters. Clever masters will give them a certain degree of freedom so that they can accomplish the task themselves. They are usually as enthusiastic as their masters.

Before washing, truffles are not particularly appealing to the eye. Experts can determine the quality of truffles from their scent. After picking a truffle, the dog will be rewarded with a piece of cheese. Before leaving the site of picking, the picker will cover the pit with soil and leaves to protect the mycelium of the truffle so that more truffles will grow. For those that are lucky, a few hours of truffle hunting in the morning may result in a few great finds. When a Burgundy or Perigord truffle is cut into halves, it shows a special texture. Its special flavor can be used to cook some of the most delicious dishes in the world.

This is the Vienna Institute of Botany. Truffles have been studied here for a long time as a special topic. Botanist Alexander Eben believes that truffles will be cultivated artificially on a large scale in the future. Like boletus, truffles are symbiotic with the soft roots of some trees. The experiment they are attempting is to graft germinant truffle substances onto the roots of young trees. Several hundred young trees have been grafted and have been growing in green houses for two years. The researchers check their growth frequently after washing off the soil. They have found that the roots are growing longer and thicker, and they are on the road to success.

In three or four years, the first batch of farmed truffles may be grown in the Austrian truffle garden. What an exciting prospect! These so called white truffles are light in color and inferior in quality. But they are still highly valued. They grow in Austrian forests and can be found by experienced pickers, usually after a storm has washed off the topsoil on hill sides and exposed the bulb like truffles. Volt Korafak begins looking along the two sides of the valley after a rainfall. His patience is often paid off. Colorful and attractive fungi grow and propagate everywhere in the forest. An ancient Siberian legend said they were driven by the magic power of the spirits of fungi.

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