Laetiporus sulphureus

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***Laetiporus sulphureus*** is a species of bracket fungus (fungi that grow on trees) found in Europe and North America. Its common names are **crab-of-the-woods**, **sulphur polypore**, **sulphur shelf**, and **chicken-of-the-woods**. Its fruit bodies grow as striking golden-yellow shelf-like structures on tree trunks and branches. Old fruitbodies fade to pale beige or pale grey. The undersurface of the fruit body is made up of tubelike pores rather than gills.

*Laetiporus sulphureus* is a saprophyte and occasionally a weak parasite, causing brown cubical rot in the heartwood of trees on which it grows. Unlike many bracket fungi, it is edible when young, although adverse reactions have been reported.

## Taxonomy and phylogenetics

*Laetiporus sulphureus* was first described as *Boletus sulphureus* by French mycologist Pierre Bulliard in 1789. It has had many synonyms and was finally given its current name in 1920 by American mycologist William Murrill. *Laetiporus* means "with bright pores" and *sulphureus* means the colour of sulphur.

Investigations in North America have shown that there are several similar species within what has been considered *L. sulphureus*, and that the true *L. sulphureus* may be restricted to regions east of the Rocky Mountains. Phylogenetic analyses of ITS, nuclear large subunit and mitochondrial small subunit rDNA sequences from North American collections have delineated five distinct clades within the core *Laetiporus* clade:

* Conifericola clade: contains species that live on conifers, such as *L. conifericola* and *L. huroniensis*. All of the other tested species grow on angiosperms.
* Cincinnatus clade: contains *L. cincinnatus*
* Sulphureus clade I: contains white-pored *L. sulfureus* isolates.
* Sulphureus clade II: contains yellow-pored *L. sulfureus* isolates.
* Gilbertsonii clade: contains *L. gilbertsonii* and unidentified Caribbean isolates.

## Description

The fruiting body emerges directly from the trunk of a tree and is initially knob-shaped, but soon expands to fan-shaped shelves, typically growing in overlapping tiers. It is sulphur-yellow to bright orange in color and has a suedelike texture. Old fruitbodies fade to tan or whitish. Each shelf may be anywhere from Template:Convert across and up to Template:Convert thick. The fertile surface is sulphur-yellow with small pores or tubes and produces a white spore print. When fresh, the flesh is succulent with a strong fungal aroma and exudes a yellowish, transparent juice, but soon becomes dry and brittle.

## Distribution and habitat

 File:Chicken of the Woods Laetiporus sulphureus.jpg
*Laetiporus sulphureus* is widely distributed across Europe and North America, although its range may be restricted to areas east of the Rockies. It grows on dead or mature hardwoods and has been reported from a very wide variety of host trees, such as *Quercus*, *Prunus*, *Pyrus*, *Populus*, *Salix*, *Robinia*, and *Fagus*, occasionally also from conifers, from August to October or later, sometimes as early as June. In the Mediterranean region, this species is usually found on *Ceratonia* and *Eucalyptus*. It can usually be found growing in clusters.

### Parasitism

The fungus causes brown cubical rot of heartwood in the roots, tree base and stem. After infection, the wood is at first discolored yellowish to red but subsequently becomes reddish-brown and brittle. At the final stages of decay, the wood can be rubbed like powder between the fingers.

### Guinness world record

A specimen weighing 100 pounds (over 45 kg) was found in the New Forest, Hampshire, United Kingdom, on 15 October 1990.

## Palatability

 File:Laetiporus sulphureus dish 2010 G1.jpg
Due to its taste, Laetiporus sulphureus has been called the *chicken polypore* and *chicken-of-the-woods*. Many people think that the mushroom tastes like crab or lobster. The authors of *Mushrooms in Color* said that the mushroom tastes good sauteed in butter or prepared in a cream sauce served on toast or rice. It is highly regarded in Germany and North America.

Young specimens are edible if they exude large amounts of a clear to pale yellow watery liquid. The mushroom should not be eaten raw. Deer like to eat the mushroom.

### Allergic effects

Some people have experienced gastrointestinal upset after eating this mushroom, and it should not be consumed raw.

Severe adverse reactions can occur, including vomiting and fever, in about 10% of the population, but this is now thought to be the result of confusion with morphologically similar species such as *Laetiporus huroniensis*, which grows on hemlock trees, and *L. gilbertsonii*, which grows on *Eucalyptus*.

## Medicinal

The fungus produces the Laetiporus sulphureus lectin (LSL) which exhibits haemolytic and haemagglutination activities. Haemolytic lectins are sugar-binding proteins that lyse and agglutinate cells. These biochemical activities are promoted when bound to carbohydrates.

## Cultivation

Compared with species such as *Agaricus bisporus* (button mushroom) and the oyster mushroom, commercial cultivation of *Laetiporus* is limited. However, it can be cultivated; the most dependable and rapid production of this mushroom is indoor cultivation. The mushroom may or may not require the heat and moisture that gilled mushrooms do, depending on the strainTemplate:Citation needed. Fungal development is sensitive to carbon dioxide levels and light conditions. Artificial cultivation on synthetic substrates has been achieved.

## References

1. ↑ 1.0 1.1 Template:Cite book
2. ↑ 2.0 2.1 Kuo, Michael (March 2005). *Laetiporus sulphureus*: The Chicken of the Woods. *Mushroomexpert.com*. Retrieved on February 23, 2010.
3. ↑ Template:Cite journal
4. ↑ Burdsall, Jr., Harold H.; Banik, Mark T. (2001). "The genus Laetiporus in North America". Harvard Papers in Botany 6 (1): 43–55.
5. ↑ Laetiporus sulphureus. *New Jersey Mycological Association*. Retrieved on February 22, 2010.
6. ↑ Breitenbach J., Kränzlin F. (1986). Fungi of Switzerland, Volume 2: Non-gilled fungi. Verlag Mykologia, Luzern, Switzerland Template:ISBN.
7. ↑ Kyriakou T., Loizides M., Tziakouris A. (2009). Rarities & Oddities from Cyprus. Field Mycology 10 (3): 94–98.DOI: 10.1016/S1468-1641(10)60600-7
8. ↑ 8.0 8.1 Template:Cite book
9. ↑ Template:Cite book
10. ↑ Template:Cite bookTemplate:Page needed
11. ↑ 11.0 11.1 Template:Cite bookTemplate:Page needed
12. ↑ Phillips, Roger (2010). Laetiporus sulphureus. *Roger's Mushrooms*. Retrieved on February 23, 2010.
13. ↑ Template:Cite book
14. ↑ Volk, Thomas J. (July 2001). Laetiporus cincinnatus, the white-pored chicken of the woods, Tom Volk's Fungus of the Month for July 2001.
15. ↑ Template:Cite journal
16. ↑ Akavia, Eden. New cultivation protocols of gourmet edible exotic mushroom.

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