Red Tree Brain Fungus

Fall may be peak mushroom season on PEI, but fungi can be found at all times of year.  One that I’m seeing a lot right now is the wonderfully-named Red Tree Brain Fungus (Peniophora rufa). 

Photo: Red Tree Brain Fungus (Peniophora rufa) on PEI.

If you’ve followed my Mushroom Monday series, you’ll know that all mushrooms are fungi, but not all fungi are mushrooms. (And if you haven’t, you can find the series in the Fungus Profiles section of this blog).

What we think of as fungi are just fruiting structures, like Apples on a tree. The fungus itself is a thread-like network of mycelia that lives inside whatever the fruit is growing on – often soil, wood, dung, or other organic matter. Just like an Apple looks very different from a Blueberry, fungal fruiting structures come in a variety of shapes and sizes. This includes our familiar cap-and-stem mushrooms, as well as round Puffballs, shelf-like Polypores, finger-like Coral Fungi, and crust- or wart-like species including Red Tree Brain Fungus, among others.

I love brightly-coloured fungi. You can spot Red Tree Brain Fungus any time of year, but the red hue of younger specimens is particularly eye-catching against the winter snow (the fungus gets darker and more purple with age). Red Tree Brain Fungus has pliable cell walls that allow it to expand in wet conditions and contract when it’s dry; the recent rains and wet spring snow have made this species plump up and really stand out. I usually find it pushing through the bark on dead Poplar (as seen here), but it sometimes grows on other hardwoods as well.

Red Tree Brain Fungus is primarily a saprobe, which means it breaks down and recycles dead organic matter. Different types of saprobes promote different types of recycling. Red Tree Brain Fungus is one of the white-rot fungi, leaving behind lots of cellulose (a carbohydrate) which promotes nitrogen-fixing bacteria and wood-eating invertebrates. In this way, it contributes to healthy forest soils, available nitrogen, and forest biodiversity. Saprobes not only allow other plants and animals (including us) to live, they also keep us from being buried under piles of undecomposed dead things!

As a final note, nature is more a fierce battleground than a serene paradise. We sometimes notice the obvious predator-prey relationships but forget that every living thing is competing for survival, even fungi. For example, Witch’s Butter (Tremella mesenterica) is parasitic on the mycelium of Red Tree Brain Fungus and its relatives. Even the most boring-looking piece of deadwood can have life-and-death action happening inside.

Warmer temperatures and longer days inspire many of us to spend more time outside. Early spring – before leaves appear – is a great time to spot often-unnoticed parts of PEI Untamed!

(And if you'd like to learn more about PEI's beginner-level fungi, check out my upcoming Zoom workshop: https://www.pei-untamed.com/event-details-registration/intro-to-mushrooms-zoom-workshop).