Jack-o-lantern Mushrooms

Jack-o-lantern Mushrooms at the base of a tree stump.

     In honor of Halloween, here is a fascinating and fitting fungus: the Jack-o-lantern Mushroom (Omphalotus illudenss). These bright orange mushrooms can be found growing in clumps on decaying stumps and base of dead trees in the Fall. A fairly good identification trait is that they have gills that run part way down their curved stalks. As they grow older they, they often are sunken in the middle top of their caps as well.

The gills run part way onto the crooked stalk.

     Jack-O Lanterns are most famous for an eerie, though rarely seen, trait, as they can glow green in the dark! Conditions have to be perfect for this to happen though. They must be mature, but not too old, and should be moist. It also helps if it is very, very dark and you concentrate on looking at their gills. I've tried this many times but have not been rewarded that often. For the best chances, make sure you let your eyes get accustomed to the dark a few minutes, use the freshest mushrooms you can find, stare at their gills, and make it as dark as possible. Jack-o-lanterns are among the 71 or so fungi (out of over 100,000 species worldwide) that show bioluminescence.

The best my camera could do to capture the bioluminescence of the mushroom gills.

     People have confused them for edible Chantarelles (which do not grow in clumps for the most part, do not have gills running down the stalks, and often grow on the forest floor rather than on stumps or base of trees). Jack-o-lanterns are supposed to have a soapy taste. Take a bit of care though since these are considered to be poisonous mushrooms. Ingesting them won't kill you, but you will be in terrible gastric distress for a couple of days (and they say, perhaps wishing you were dead).
     It is this poisonous quality that is being studied in cancer research. It appears that several types of cancer are affected by the chemicals found in Jack-o-lanterns. They also seem to have anti-fungal and anti-bacterial properties as well.
     Although not unpleasant in smell, these fungi tend to attract a lot of flies and other insects, especially once they start to decompose. I've seen lots of fungus gnats, various species of flies, and even yellowjackets all in great abundance around Jack-o-lantern Mushrooms. It may be that these insects help disperse the spores, but they may just be feeding on the decomposing flesh also. Here are a couple of photos showing some.

A pair of either Drosophilid or Lauxaniid flies attracted to the mushrooms.

A fly feeds on a Jack-o-lantern Mushroom.

     Jack-o-lantern Mushrooms are definitely one of the more fascinating types of fungi. There orangish color, emergence near Halloween, and eerie green glow I thought made them very appropriate for a Halloween post. Just don't try and make pie from them...

Jack-o-lanterns emerging