Mushrooms - Edible,Toxic and Medicinal

Button Mushooms (Agaricus bisporus), a common edible mushroom. Credit: Wikimedia Commons

Many species of mushrooms seemingly appear overnight, growing or expanding rapidly. This phenomenon is the source of several common expressions in the English language including "to mushroom" or "mushrooming" -expanding rapidly in size or scope and "to pop up like a mushroom" to appear unexpectedly and quickly. In reality all species of mushrooms take several days to form primordial mushroom fruit bodies, though they do expand rapidly by the absorption of fluids.

Morels are toxic if eaten raw.Credit: H. Krisp, Wikimedia

The cultivated mushroom as well as the common field mushroom initially form a minute fruiting body, referred to as the pin stage because of their small size. Slightly expanded they are called buttons, once again because of the relative size and shape. Once such stages are formed, the mushroom can rapidly pull in water from its mycelium and expand, mainly by inflating preformed cells that took several days to form in the primordia.

All mushrooms are fungi, but not all fungi are mushrooms.  For those fungi that produce them, the mushroom plays a similar role to a flower or a fruit in plants.  Some part of each mature mushroom produces microscopic spores that are similar to pollen or seeds, sometimes numbering in the trillions.  The rest of the fungal organism typically lives in the soil, wood, or some other material and is composed of thread-like strands known as mycelium

The toxic mushroom Amanita muscaria, commonly known as "fly agaric"

 Poisonous mushrooms

The common death cap (Amanita phalloides) or its relatives can be fatal if eaten.  There are several other species that can be deadly if eaten, but all known species can be handled safely.  However, relatively few mushroom species are dangerously poisonous.  Many more species, including the commonly illustrated Amanita muscaria, can cause stomach pains, vomiting, or diarrhea.  Even the popular morel is toxic if eaten raw.

Ganoderma lucidum has demonstrated an anti-cancer effect.Credit:Patrick Harvey, Mushroom Observer

 Medicinal mushrooms

Some species of mushrooms have been used as medicine for thousands of years, particularly in China and Japan. Some of the immune- enhancing and anti-cancer effects of traditional species such as Ganoderma lucidum and Trametes versicolor have been demonstrated scientifically.  Regular consumption of oyster mushrooms has been shown to reduce cholesterol.

Oyster mushrooms are thought to help reduce cholesterol.Credit: Richard Sullivan, Mushroom Observer

 References

 ·         Arora D. (1986) Mushrooms Demystified, 2nd edition. Berkeley, California, USA: Ten Speed Press.

·         Volk TJ. (2002) The humongous fungus--ten years later. 2012 (9/26).

·         Gill SK, Rieder MJ. (2008) Toxicity of a traditional chinese medicine, Ganoderma lucidum, in children with cancer. The Canadian Journal of Clinical Pharmacology 15(2).