Laricifomes officinalis

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***Laricifomes officinalis*** is a wood-decay fungus in the order Polyporales. It causes brown heart rot on conifers, and is found in Europe, Asia, and North America, as well as Morocco. It is commonly known as **agarikon**, as well as the **quinine conk** because of its extremely bitter taste. DNA analysis supports *L. officinalis* as distinct from the genus *Fomitopsis*.

The conks were once collected extensively for production of medicinal quinine, which they were thought to contain, because of the bitter taste of the powdered conk. However, they do not contain quinine, and have no anti-malarial properties.

The distinctive conks can be large, as much as two feet long, hoof-shaped or columnar. They are soft, yellow-white when young, soon becoming white and chalky throughout. The decay is brown, cubically cracked, with thick white felts in large cracks. The taste of both conks and felts is bitter and distinct for this species. A single conk usually indicates complete cull. Infected trees can be habitat for snag-nesting species.

## Medicinal use

*L. officinalis* was used by the Ancient Greeks to treat consumption (tuberculosis) according to the writings of Pedanius Dioscorides in 65 AD, and by some indigenous people to treat smallpox. The presence of Agarikon at burial sites may indicate that its use was once widespread.

Mycologist Paul Stamets has performed numerous investigations of the biological activities of Agarikon. Agarikon extracts have demonstrated antiviral activity against a range of viruses *in vitro*. This activity has been specifically observed against pox family viruses, HSV-1 and HSV-2, Influenza A, Influenza B, and *Mycobacterium tuberculosis* *in vitro*.

Other researchers have identified novel chlorinated coumarins in the organism which demonstrated notably low minimum inhibitory concentrations against the *Mycobacterium tuberculosis* complex.

## Conservation

Wild Agarikon is only found in old-growth forests Template:Citation needed, and grows on conifers, particularly Douglas-fir (*Pseudotsuga*) and larch (*Larix*). Conservation of wild populations of *L. officinalis* is a concern because of loss of ancient forest habitat. Because it is difficult to maintain long-term genetic integrity of laboratory-grown strains, it is necessary to preserve the mushroom in the wild.

## Ethnomycology

*Laricifomes officinalis* was important both medicinally and spiritually to indigenous peoples of the Pacific Northwest Coast of North America, such as the Tlingit, Haida, and Tsimshian. *L. officinalis* was referred to as the "bread of ghosts" in local languages, and carved fruiting bodies marked the graves of tribal shamans.

## References

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6. ↑ Hagle, Gibson, Tunnock. A Field Guide to Diseases & Insect Pests of Northern & Central Rocky Mountain Conifers. USDA Forest Service: 2003, pg 29
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10. ↑ [Patent Antiviral and antibacterial activity from medicinal mushrooms].
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## External links

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* Index Fungorum
* USDA ARS Fungal Database
* Brown Trunk Rot, *Trees, insects and diseases of Canada's forests*, Natural Resources Canada
* Agarikon, Cornell University Mushroom Blog

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