wwh: I was reading tonight through some old posts, and came across one of your illuminating ones. You included a link to a mushroom site, and there I read with some degree of fascination about bioluminescence.

Here 'tis:

One element of folklore that is for real is "foxfire," the colloquial name for the natural bioluminescence exhibited by an assemblage of gilled fungi that invade wood. Most common among mushroom species from the tropics, the responsible photogen "luciferin" produces light ranging in color from blue to green to yellow. Rarely formed in freed spores, it can cause the ground beneath fruit bodies to glow at night. But more often it is the mushroom itself or its aggregated hyphal strands that luminesce. In North America two prevalent examples are (1) the rhizomorphs of the virulent hardwood parasite Armillariella mellea that permeates downed trunks; its fruit body is the edible Honey Cap or Banana Mushroom responsible for aborting fructifications of the agaric Entoloma abortivum, and (2) the gills of the pumpkin-colored poisonous mushroom (Omphalatus olearius) that is frequently mistaken for a chanterelle; known appropriately as Old Stomachache or Jack O'Lantern, its tissues have the distinction of turning green on cooking -- a character not seen for any edible mushroom.

http://www.mpm.edu/collect/botany/mushroom.html

So, in the above we learn more about triboluminescent cousins foxfire and a new kind of Jack O'Lantern.

Best regards,
WW