Omphalotus nidiformis, or the ‘ghost fungi’ as it is commonly known, is a species of fungi which is quite often found growing in southern Australia, which of course means Tasmania. Generally found at the base of Eucalyptus or exotic trees on living or dead wood.

What does it look like in the day?

It is quite a large species reaching up to 20cm in diameter, perhaps even larger. As with most fungi, it depends on what day you visit it as to its colour. Ranging from white to cream to shades of brown. Sometimes it might show a purple or blue tinge, and quite often the central area is darker or more heavily coloured. Can be confused with other species of fungi, such as Pleurotus australis, but the others don’t glow, so if it is dark then you shouldn’t be easily confused.

The fruitbodies (thats the mushroom looking bit) is a fan type of funnel shape. Yes, that is two different shapes, but similar. Of course the nature of fungi, is that at every different stage of life it can look either the same or completely different. Which can make identification a difficult task at times. The margins of the cap can be inrolled when younger, flattening out and even curving up when aged. Generally it is also slightly wavy and depressed in the centre.

Gills are whitish and decurrent. Decurrent means that the gills are attached to the stipe and extend down it for some way. It also has a white spore print, which sometimes you can tell on some fungi and others not so much. If fungi is growing in a clump over the top of each other, you can sometimes notice the colour of the spores as they land on the one below them. Knowing the spore print colour can be very useful for identification.

The stipe (that’s the stem) is normally central, although can be slightly off centre too. It is cream to grey and roughly 8cm long and 2cm wide.

You won’t usually find just one little fruitbody hanging out on it’s own. Omphalatus usually grow in a clump, fanning out all over each other.

What does it look like at night?

Nothing much about the description changes at night. Except for the fact that it glows green in the dark! It’s our very own glow in the dark mushroom. When we were kids we thought glow in the dark stars on our ceiling was pretty awesome. Little did we know nature already had that stuff covered for years before us.

Technically, to say it glows in the dark is a little bit of a lie. It also glows in the day too, except being the day and having the sun about, we just can’t see it.

How does that glowing thing work?

Remember reading about bioluminescent algal blooms? No? If not, knick over real quick and refresh your memory ‘Red tide that is blue’.

It’s the same here. Luciferin-luciferase reaction. A bit like photosynthesis but the opposite way. Rather than light energy being converted to chemical energy, this time chemical energy is converted to light energy!

Luciferin is the bit that makes the light, but until the luciferase gives it the nod it just hangs out, doing nothing much I guess. We call luciferase the catalyst, which means it is the one that starts the ball rolling. When there is another substance around, such as oxygen or ATP, the luciferase lets the luciferin and the other substance combine. When they do you get another reaction, which produces light (energy) and leaves the now oxidised luciferin to become oxyluciferin. And thats how bioluminescent babies are made (not real babies).

Why? Oh why, do you glow so?

Is it to attract potential spore dispersing insects? Perhaps, but probably not according to a study done in 2016 (link to the paper at the end). These four guys set up a pretty decent experiment to see if more insects were attracted to the traps with the glowing fungi than the traps without any fungi. There was no difference. However, I didn’t come across any other specific Omphalotus studies. There were other studies, on other species, which did show that bioluminescence attracted insects. These other fungi species grew in different habitats though, with different insects and different abiotic factors. They also luminesced at night rather than all the time like Omphalotus.

Another hypotheses is that the bioluminescence is a by-product of metabolic processes. In other words, rather than releasing excess energy as heat, it releases it as light. Considering that Omphalotus emits light all the time, this hypotheses could fit. Of course I haven’t researched all this as intensely as I would if I was writing a legit paper, so I am leaving it all up in the air! Perhaps the answer is there to find if you search google scholar and read enough literature on it. Let me know if you turn up something!

How to photo Omphalotus

I can’t remember the exact settings I used to be honest. I only photographed it once and it was a few years back, and I can’t even find my photos, oops. The same as you would with any night photography. Stick your camera on a tripod, boost your ISO as high as it can go without being awful grain. Set your aperture as wide as possible. Put your shutter on a decent length of time, maybe start at 10 seconds… Then fiddle from there. If it is all too dark, try a longer shutter or boosting the ISO. Trial and error baby, trial and error…

All the photos here are by Scott Corkill. Because I don’t have any, but not only that, I freaking loooooooove these shots. No offence to anyone else who has photographed it of course, but these are some of the best shots I’ve seen. So if you want better photography tips than I just gave you, go and message him via his page. I’m sure he will help!

Things to check out…

That paper on insects and Omphalotus is here:  Weinstein, P., Delean, S., Wood, T. and Austin, A.D., 2016. Bioluminescence in the ghost fungus Omphalotus nidiformis does not attract potential spore dispersing insects. IMA fungus, 7(2), pp.229-234.

Tas Fungi website: http://www.tasfungi.com.au

Scott Corkill Photography: http://www.facebook.com/Scott-Corkill-Photography

‘A Field Guide to Tasmanian Fungi’: http://www.utas.edu.au/tasmanian-fungi/a-field-guide-to-tasmanian-fungi

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