The Carlisle Mosquito Online

Friday, April 20, 2007


Biodiversity Corner: Blue stain fungus

We haven't had a fungus in the Biodiversity Corner since February 16 and while you know I have a fondness for fungi, I do like to cover things that other people are finding. So imagine my delight last Thursday at the Peter Alden talk about local changes in flora and fauna between Thoreau's time and today, when Bonnie Miskolczy showed me the stick she had found in the woods. It was completely permeated with the blue stain fungus. I had arrived at the talk without an idea for this week's topic. I left with a topic for the column, a head full of new knowledge about changes in the local ecosystem, and a pocketful of blue stain fungus. My cup runneth over.

Name: The blue stain fungus is probably Chlorociboria aeruginascens. It has an almost identical twin with a very similar name, C. aeruginosa. They are differentiated microscopically. C. aeruginosa has spores that are about 5 microns longer and 2 microns wider but this species occurs less frequently — or so they say. The species name is made up of aerug meaning blue-green, green or deep green and the suffix -ascens meaning almost or somewhat (or -osa meaning fullness or abundance). It also goes by the common name of green stain, and sometimes green oak.

When and where found. Bonnie found her blue stick in the Estabrook Woods on April 7 — if not in Carlisle then close to Carlisle. Liz Loutrell also found some in Estabrook on April 13. If you follow the trail the Minutemen took from the end of Kibby Place towards the North Bridge, you will pass some very large logs on the left side of the path that are hosting Chlorociboria. I also find it quite often in the Towle Land and Great Brook Farm State Park. I have never seen it on standing trees, only on fallen logs and sticks — often with no bark. It is said to favor oak but I find a lot on birch.

Distinguishing characteristics. It's blue! It's a bit of a jolt to come upon it in the woods because the color seems unnatural — well maybe not for feathers or flowers, but certainly for wood. The fungus produces secondary metabolites which stain the wood blue. It's not exactly the fungal equivalent of yellow snow — the color is long lasting and the wood has been used by humans for artistic effect. Cabinet makers working in a genre known as Tunbridge Ware sometimes incorporated it into inlaid wooden boxes and chests.

Mushrooms. We detect the presence of most fungi by their fruiting bodies, the mushrooms. This is an exception. It is easy to spot when it is not fruiting and once found you can inspect the log for mushrooms. They are as blue as the stain in the wood. They have a short stalk and are cup-shaped when young and more saucer-shaped when mature. They are about a quarter inch in diameter. When you find one, you are likely to find many.

In the mysterious cosmic scheme of things there must be a connection between Peter Alden, me and the blue stain fungus. The first time I found this fungus in fruit was at a Bio-blitz event at Odiorne State Park in New Hampshire where Peter was functioning as honored guest and chief motivator. He witnessed my dance with the blue stain log which was covered with little blue mushrooms.

Edibility. The first question about mushrooms is generally, "Is it edible?" The "normal" mushroom books list this one's edibility as unknown, meaning people have yet to try it and report on their experience. David Arora, who has a freer style, categorizes it as "indisputably inconsequential."

References. Alan Bessette, Arleen Bessette, David W Fischer, Mushrooms of Northeastern North America; David Arora, Mushrooms Demystified.

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2007 The Carlisle Mosquito