Sunday, 10 February 2013

The Piltdown Mushroom

Since I study mushrooms I sometimes receive images from people asking for identifications. One of those images was something I had never seen, nor seen anything in the literature that vaguely resembled it. It was a rose coloured cup fungus with a papilla in the centre, and was growing on the trunk of a living shrub. The bark of this shrub was perfectly healthy, showing no signs of pathology.

The first possibility that came to mind was a species of ascomycete cup fungus, but to my knowledge none of those has a little bump in the middle. The next possibility was a bird’s nest fungus. These often grow on wood, and have peridioles, spore bearing structures, in them. They, however, have more than one peridiole, and do not grow on living trunks. It was a total mystery to me, so I advised the enquirer to contact several people with a better mycological knowledge than mine.

I was very intrigued by this fungus. Maybe it was a totally undescribed genus. The description of its location was beside a trail close to where I live, so I decided to set out on an expedition to locate it. Such a find should be documented with a herbarium voucher. Since I walk this trail, and know its fungal flora very well, it was perplexing that such a unique species could be growing there.

Upon setting out I met somebody who asked me where I was going, and I explained that this very unusual cup fungus had been seen along the trail, and I was going on a search for it. She replied that she had seen them a few days earlier, and that they were very clever. Somebody with a knowledge of mycology must have made them!

After a careful search along the trail, there they were. Seven of them on a vine maple (Acer circinatum) trunk surrounded by the cat tail moss (Isothecium myosuroides). Creatively constructed from pink plastic, with long stems inserted into the epiphytic moss carpet. 

Piltdown Mushroom
Photo by Rosemary Taylor

The amazing plastic cup fungi. Artificial ascomycetes in the prime of maturity. It brought to mind the Piltdown man hoax of a century ago, or the photos of flying saucers that used to intrigue me when I was young. The images certainly looked very real. How long will they fruit on that tree?                                                                                   

Tuesday, 29 January 2013

Agarikon - Old Growth Medicine

In the old growth forests of coastal British Columbia there is a fungus which has been used medicinally for 2000 years. It is a bracket fungus called agarikon or quinine fungus (Laricifomes officinalis, Fomitopsis officinalis). Bracket fungi are the shelf shaped wood decay ones that grow on trees and logs. Most of them are perennial and continue to grow for many years. They make a new layer of spore producing tubes on the underside of the bracket each year. If a bracket fungus is cut in half, you can see the annual layers analogous to the annual rings in a tree trunk.

The agarikon is one of these bracket fungi, but a rare and unusual one. It grows high up in the canopy of very large, old trees, and the brackets can live for many decades. If it is on the trunk it is hoof shaped like many other shelf fungi. On a branch, however, it tends to grow vertically downwards, like a thick white icicle. If you see one, which is unlikely, it is usually well beyond reach. To actually get your hands on it, you need to find a big fallen tree. The generic name refers to Larix, the larch tree, for in Europe it grows on old larch trees. In BC its host is Douglas fir. Like all such fungi, what we see is the fruiting body, essentially a spore producing flower. The growing parts of the organism are felts and hyphal threads which grow through the tree year after year, as it is a parasite on these old trees. 

The fruiting body is a chunky white structure and the annual layers are quite apparent even without sectioning it. Unlike other shelf fungi it is soft and chalky on the surface, and is very bitter. Identifying fungi by taste is a common practice among mushroom lovers, but a warning is in order. If you taste an unknown fungus do not swallow any of it. There are many toxic fungal compounds. 

Agarikon (Laricifomes officinalis)

In all the years of studying fungi, I had never seen the agarikon in nature. Except for two specimens I retrieved from mushroom shows, of unknown origin, it remained very elusive. That was until last year, on a Nature Vancouver hike through an old forest near Hope. A centuries old Douglas fir had recently fallen beside the trail, and attached to it was an agarikon! Its chalky white surface was unmistakable.

What is so special about this fungus? Its rarity is, of course, one of the significant features. It only grows on old trees, and even in old growth forests it is uncommon. As old growth forests are now uncommon, the agarikon is even more uncommon than it once was. Although it has been known in Europe since at least Roman times, it is almost extinct there now. Very few old growth stands remain in Europe. There are reports that it now survives only on larches in the Slovenian Alps. 

Strengthening the case for protecting agarikon and its old forests, is research on the medicinal potential of this fungus, and the importance of maintaining as much of its genetic diversity as possible. This research has uncovered both antibacterial and antiviral activity. Agarikon has been used traditionally to treat both tuberculosis and smallpox, and First Nations probably also used it as a medicine. Figures carved from agarikons were sometimes placed on the graves of shamans.

The potential of this fungus is yet another reason for preserving our old growth forests. The loss of agarikon could very well result in the loss of effective treatments for serious diseases. There are also other fungi restricted to old growth stands, and the medicinal properties of fungi have been poorly researched. With the rapid advances in molecular biology and biochemistry that are now taking place, the promise of agarikon and other forest dwellers may yet be realized, provided we protect the habitats where they dwell.