Cinnabar Polypore

On PEI, September means a few things: the end of summer, the start of school, and the return of Mushroom Mondays! Over the past couple of years, this series has introduced you to more than 40 common Island fungi (you can find these in the Fungus Profiles section of this blog). Let’s kick off the new season with a colourful one: Cinnabar Polypore (Pycnoporus cinnabarinus).

I appreciate an easy-to-identify fungus with a descriptive common name. ‘Cinnabar’ is a red-orange mineral that was once used for colouring pottery, textiles, and cosmetics. From above, the cinnabar colour of this fugus is eye-catching (inset photo). ‘Polypore’ means ‘many pores’ and is the term used to describe bracket- or shelf-like fungi that have many tiny pores underneath (main photo). No other PEI polypore sports this distinctive colour on top and bottom.

Polypores make a living by decomposing dead wood – hardwood in the case of Cinnabar Polypore. I see it most commonly on dead Pin Cherry, but it can also be found on Beech, Birch, Oak, and other hardwoods. The fungus itself lives as a thread-like network of mycelia inside the dead wood and produces these colourful brackets when it’s ready to reproduce. The mushrooms we see are the fruit of the fungus.

Cinnabar Polypore is one of the white rot fungi, digesting lignin and leaving behind bits of cellulose (a carbohydrate) that can be used by nitrogen-fixing bacteria and wood-eating invertebrates. White rot fungi are ecologically important, contributing to healthy soils, available nitrogen, nutrient cycling, and biodiversity. As decomposers, they also keep us from being surrounded by piles of undecomposed dead things!

The distinctive colour of Cinnabar Polypore comes from several chemicals, notably cinnabarin and cinnabaric acid. Both are effective antibiotics against a range of bacteria including E. coli, Listeria, Salmonella, and Staphylococcus. Cinnabarin, cinnabaric acid, and other compounds in the fungus have also been shown to have anti-cancer and anti-viral activity, including against the virus that causes rabies. Cinnabaric acid is present in tiny amounts in the human brain, and researchers are looking into whether it could have neuro-protective properties.

While Cinnabar Polypore rarely has much of a scent, chemicals within it can be processed into useful aromatics and flavourings such as vanillin (a key component of vanilla flavouring) and methyl anthranilate (used for grape flavouring). The colourful pigments can also be extracted for use in food, cosmetics, and textiles.

Like many polypores, Cinnabar Polypore is too tough and woody to be edible, but it is a beautiful, ecologically important, and interesting member of PEI Untamed!