Not just another mushroom

Walking in the wet green woods today I spotted some strange-looking protuberances on a severed birch trunk: pearly white and eggshell smooth, these rounded lumps could almost have been made of leather or plastic if they were not obviously bracket fungi growing out of the dead wood. These 'conks' are the fruiting bodies of polypores, a type of fungus that invades trees, usually via existing points of damage, and parasitizes the timber, causing decomposition and decay - just one of the natural processes that occur as part of the infinite cycle of life.

This one is the birch polypore Piptoporous betulinus and it's not just another mushroom, it's a prehistoric first aid kit. In 1991 tourists in the mountains on the Austrian/ Italian border came upon the shrunken, blackened body of an unfortunate climber, trapped in the ice. The corpse had already been roughly levered free before archaeologists pronounced it no recent victim of the Alpine hazards but the mummified remains of a man who died there 3500 years ago.

Ötzi, as he has come to be known, has been subjected to some of the most intense forensic examination ever carried out: his DNA, his health, his clothing, his tattoos and his baggage have all been scrutinized to extract every single detail of his prehistoric existence. Even so, it was 10 years before a CT scan revealed that he had an arrowhead lodged in his shoulder, and that, rather than being the benighted traveller or frostbitten fugitive of speculation, he was a murder victim, probably left to bleed to death.

One of the many intriguing things that the Iceman was carrying about his person were some chunks of this particular fungus threaded on leather thongs. Birch polypore has several medicinal properties: it is an antibiotic, a styptic (to stop bleeding) and a treatment for whipworm, an intestinal parasite which Ötzi was found to suffer from. Modern studies have confirmed that the fungus contains antibiotic and anti-inflammatory compounds and that betulinic acid, extracted from it, is effective against anthrax, cancer and HIV. Quite a little medical arsenal from three thousand years ago!