Friday, 16 May 2014

Chlorociboria and Patinellaria sanguinea: Colourful Wood Spalting Fungi

Patinellaria sanguinea produces tiny black discs and stains wood coral red
Patinellaria sanguinea stains wood coral red. 
It’s easy to forget while collecting fungi that the ones we find growing on wood and elsewhere are only their fruiting bodies—the actual organism is usually hidden, its mycelium buried deep in wood or soil. But the microscopic mycelium of some wood-loving fungi make it very clear just how large an area they’ve taken over by staining the wood they’ve colonized. This staining, which can sometimes be dark lines, other times extensive areas of colour, is called spalting.

Blue-green wood spalted by the cup fungus Chlorociboria.
Wood stained blue-green by the fungus Chlorociboria.
The fairly common Chlorociboria aeruginascens and its sister C. aeruginosa, which can only be differentiated microscopically, stain the wood they’ve colonized a stunning blue-green with the pigment xylindein. This beautiful blue wood has been used by woodworkers since at least the 15th century, primarily in inlays (see examples here). It’s such a striking colour that studies are underway to find a way to inoculate various forest trees with Chlorociboria to enhance the value of the lumber. Personally, I’m impressed that anyone has ever found a piece of this blue wood in good enough shape to use for anything other than as a conversation piece. In my experience, whenever I find it, the wood is already so decomposed I can easily pull it apart with my fingers.

Chlorociboria produces blue-green fruit bodies.
Chlorociboria produces gorgeous blue-green fruit bodies.
Serendipitously, I recently came across a much more uncommon helotiale that also stains wood.

Slightly dried discoid Patinellaria sanguinea with subiculum.
Slightly dried Patinellaria sanguinea discs and subiculum.
A month or so ago, I brought in a branch I’d left outside for the winter that had had the beginnings of a mystery purple crust growing on it in the fall. I hoped that by giving it a little warmth and moisture it might revive and offer me some spores to help in its identification. But nothing happened. Well, actually something happened—the purple corticioid started decaying. I was about to relegate the branch to the kindling pile when I noticed that in a couple of places its surface was oddly coloured with reddish-pink spiderwebby fuzz. I assumed this was just an unusual mold, but when I got out my loupe to inspect it I was surprised to see a multitude of minute blackish discs embedded in it. Helotiale type discs. Hmm.

Patinellaria sanguinea under microscope
Amazing colour of "black" Patinellaria sanguinea fruit bodies under the microscope.
When I put a sample under the microscope I immediately saw that the pink fuzz was not a mold, but a hyphal mat, or subiculum, that clearly belonged to the blackish discs. Not only that, but, when sectioned, the “black” discs were actually quite strikingly coloured. There were even some asci and spores.

ellipsoid to clavate spores of Patinellaria
Wonky ellipsoid to clavate spores of Patinellaria.
I didn’t have a clue what it was, or even how to start looking to find a name since nothing like it was in either Fungi of Switzerland or the brand new Ascomycete Fungi of North America. I got my knife out and carved a few chunks off the branch to dry for later study. It was only then that I realized my little ascomycete had another interesting characteristic: it had stained the wood a gorgeous coral red. Surely, I thought, this would make finding its identity easier. But still no luck on Google or Ascofrance or anywhere else.

Days passed. I was doing an unrelated image search for another minute black disc, Patellaria atrata, this one sans color, when halfway down the page a picture jumped out at me. It clearly showed exactly what I had accidentally grown—mini blackish discs with a pinkish red subiculum. And they had a name. Panitellaria sanguinea.

I have not been able to find out much about this little curiosity, which has also been known as Durella sanguinea and Peziza sanguinea, other than that it’s rare, grows in North America and Europe, and apparently prefers hardwoods. If anyone can add anything else, I’d be grateful.

More Info:

Tom Volk’s Chlorociboria page
Panitellaria sanguinea on Mycoquebec
Panitellaria sanguinea on Mycokey
Robinson, S.C., Tudor, D., Snider, H., Cooper, P.A. 2012. Stimulating growth and xylindein production of Chlorociboria aeruginascens in agar-based systems. AMB Express 2(15).
More about spalting: Northern Spalting

George Grant Hedgcock. "Studies Upon Some Chromogenic Fungi which Discolor Wood." St. Louis, 1906


  1. Hello. I am interested in sharing the unusual things I have found.

  2. I see red on bark of hardwoods.
    But no black spots.