Surprisingly, there are quite a few forms of mushroom that glow in the dark. The Brazilian ‘flor-de-coco’ was discovered in 1840 and reportedly glows bright enough you can read with it. A glowing mushroom is totally my next bedroom accessory. Although I’m not sure how to care for it… will I have to feed it?
The jack-o-lantern fungus in the United States is a poisonous mushroom easily mistaken for delicious chanterelles. I recommend you always mushroom pick at night – if it glows green, don’t eat it. As for how you are going to find the non-glowing, edible mushrooms in the dark…. That’s not my problem. I don’t eat mushrooms. But at least you won’t be dead of poisoning, right?
Honey mushrooms don’t glow entirely, but apparently only have glowing filaments. They grow in rotting wood, and these are the mushrooms that often (but not exclusively) make foxfire – the phenomenon where rotting logs seem to glow blue-green after dark! Now that’s neat. Maybe I could use one of these as a feature bench seat in my garden. It’d go well with the pool lights. In other parts of the world foxfire is also known as will-o’-the-wisp and faerie fire. Well we all know how often those plot points crop up in fantasy novels.
Fungus glows for the same reason that fireflies do – by burning luciferin (sounds deliciously hellish). Fireflies, however, only burn it in bursts, while mushrooms do it all the time. Show offs. They even do it during the day – we just can’t see it. Now that’s downright wasteful.
The real puzzle is why do mushrooms glow at all? There are three usual reasons for bioluminescence:
- To attract a mate;
- To frighten off predators
- To attract potential meals.
Now mushrooms are not mating, and when it comes to predators, many are already poisonous. So far as we know, mushrooms also aren’t eating anyone else.
So what is the glowing mushroom trying to do? In some species it appears glowing is linked to metabolism – but not in others! Curiouser and curiouser.
Now you might be wondering why I cared about glow-in-the-dark fungus at all – and I promise I am not writing will-o’-the-wisps into my book.
If you haven’t been following the ITCOTD Monday Morsel series, you might not be aware there are catacombs under the castle that serves as the main setting for my next book. Essentially our hero is underground here without a light source and I suddenly needed him to be able to see something. Glowing fungus seemed like a solution, but I didn’t know if there was in fact any such thing. Apparently there is even a species in Australia that glows but that was news to me – certainly I have never seen it. And you can get these fungi in caves. I also didn’t know how bright such a mushroom might glow and if it would be bright enough for what I needed.
So off I trotted to ask Google. Who said you never learn anything real in fantasy?