Fungi – the ‘good’ and the ‘bad’

Ramaria stuntzii

Fungi have been around for well over 600 million years. Their job description never did say ‘do good for humans’. That’s just our good luck. When we think of the ‘bad’, we think of things like mildew in our books or mold on wall or ceilings. The older of us remember fungi feeding on our shower curtains. That encouraged glass shower doors, because we didn’t find bleach compatible with showering. Some of us will recall ‘athlete’s foot’ or ‘ringworm’ – not a worm, but a fungal infection of the skin. There’s quite a few fungi that forage on our skin, but that’s a tiny part of their job description. There are more than a million fungi species on the planet, but only about 300 make people sick. A few can be lethal. Here ‘good’ and ‘bad’ refers to edibility of a few species found at Brooksdale. Actually, fungi do far more good than bad.

What good are fungus?

The good that fungi do us, and most other living things, is a simple product of their job description: decompose everything organic. That includes some things that some of us wouldn’t immediately recognize as organic – like shower curtains. You develop a lot of talents over 600 million years or so and there is little that fungi cannot or will not do. That’s why we use them and their products every day, often without knowing it.

Food & drink All of us enjoy fungi as tasty morsels themselves or as their contribution to other products – bread, tempeh, dumplings, soy sauce, Stilton or Roquefort cheese and a range of alcoholic drinks.

A huge range of industrial processes They produce industrial chemicals like citric, gluconic, lactic and malic acids, or industrial enzymes, including lipases for detergents, amylases, cellulases, invertases, proteases and xylanases.

Cleaning up our worst messes Fungi can turn insecticides, herbicides, pentachlorophenol, creosote, coal tars and other undesirables into CO₂, water and basic elements. They even appear capable of biomineralizing uranium oxides.

Safe insecticides They’re already out there, but we can concentrate them.

Food and shelter About 90% of our crop plants and timber trees rely on mycorrhizal fungi to grow.

Our health Almost all of us have relied on penicillin more than once; about a quarter of us will sometime benefit from fungal-based adjuvants to cancer therapy.

These are mighty big gifts and fungi don’t charge a thing. There is a much bigger gift.

Our lives Without fungi the living world would quickly stop. Losing mammals, birds, fish, amphibians or reptiles would not do that. But once things no longer decomposed and nutrients were no longer recycled and available, nothing that could not make its own nutrients would be around – that’s most living things. Even if we just lost the mycorrhizal fungi and not the decomposers, we’d be in a world of hurt. The mycorrhizal fungi assist plants in taking up useful nutrients and water, screening out toxic elements and fending off plant enemies. The vast majority of rooted plants and many mosses rely on fungi to take in nutrients and water.

Some ‘bad’ guys

Here our ‘definition’ defines what happens if we eat them. The vast majority of fungi are unpalatable, tasteless, too small to chase, too woody or too squishy to eat. That’s compelling evidence they weren’t put here to feed us. Some are ‘bad’ and can kill us.

The genus Amanita is responsible for about 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The problem is that some Amanita are cleverly disguised as something edible. There are several species within or near the forest biodiversity plots.

Amanita gemmata (Gemmed Amanita) Amanita pantherina (Panther Amanita) and Amanita phalloides (Death cap)

Amanita can be colourful.

Development of Amanita muscaria (Fly Amanita)

Toxins of Amanita have a fatality rate of about 50%; they’re particularly dangerous because symptoms are delayed 6 to 24 hrs after ingestion, by which time the body has absorbed them and it is too late to pump the stomach. Half a cap of the Death cap will kill you, unattractively. First, vomiting, watery diarrhea and abdominal cramps for a day or so, then apparent recovery for a day or so. Then liver and sometimes kidney failure, brain toxicity and death. Some folks have survived with a liver transplant. Fortunately, these fungi are relatively easy to identify. Three features are key: bulbous base, ring on the stem and flecks on the cap. Some local species, like the Booted or Grey-veiled Amanita and Death cap, do not have flecks on the cap. Local species are mycorrhizal, usually helping trees grow.

Some good guys

Given about 1.5 million fungi species on the planet, chance alone dictates that there are some that are not simply edible, but tasty. Here we have chosen to illustrate only the ‘boletes’, because as a group most are edible.

‘Boletes’ look like your typical mushroom with a cap and stem or stipe, but instead of gills they have a spongy layer of tubes. Fungophiles tend to call all Boletaceae ‘boletes’ after the genus Boletus. The family Boletaceae contains more genera; Leccinum and Suillus are also common in British Columbia. Two found in Brooksdale forest biodiversity plots or nearby are shown.

Chalciporus piperatus (Peppery bolete) showing underside Boletus zelleri (Zeller’s bolete)

Boletes are sought after because many are tasty and few are toxic. Unfortunately, they also are favourite picnic grounds for maggots – it can be a race. Strong toxicity is rare enough that many keys use taste as a distinguishing feature. Generally, you’re safe if you avoid boletes with red or deep orange pores. It might not be tasty, but won’t give you major grief. Neither of the two shown merit eating. The Peppery bolete is peppery enough to be unpalatable. A wee nibble will confirm that. Zeller’s bolete is a distinctive combination of black cap, reddish stem and yellow pores. It is edible, but definitely not one of the better boletes. The tastiest, unfortunately, have not yet been found at Brooksdale. Almost all boletes are mycorrhizal on trees. If you look at the tree species they are associated with, that helps identification.

Quiz time!

Which one below is ‘bad’? No peeking.

Answer:

Left is Amanita porphyria (Booted or Grey veiled Amanita) – veiled, well booted and poisonous.
Right is Boletus edulis (King bolete) – pores that are not reddish and much sought after. Both occur locally.

The complete report Slime molds and fungal species in and near Brooksdale forest plots has been updated and will be available.