Green discoloration of dead ligneous wood

I'd thought that the green discoloration of dead ligneous wood one sometimes sees in the forest was due to fungal activity, but somebody more knowledgeable than I told me that it was a normal process of the wood itself. I’d like to know the name for this process and what’s going on, chemically.
Thanks.

 

Fungus (Chlorociboria aeruginascens) contains a quinone pigment (xylindein). It is this compound which stains the wood.

http://botit.botany.wisc.edu/toms_fungi/morel.html
Scroll past the information on morels until you reach the section on Chlorociboria, about half-way down.
Be sure to take a look at the photos (bottom of page) of gorgeous inlaid work made from wood colored by this fungus! Beautiful.

http://en.wikipedia.org/wiki/Chlorociboria_aeruginascens

 

Thanks. Now that you mention it I remember seeing those beautiful little fruiting cups on the green wood.