Fruit in a Cave

Report from George Lanz:
"While performing a bat survey at Breakdown cave on January 24, I stumbled upon this gorgeous mushroom formation. The picture is fascinating! If you look closely you will make some interesting observations.
First, the mushroom is growing on what appears to be a walnut or hickory(?) shell. Second, there seems to be a web just above it. It appears that a troglobitic arachnid is perhaps feeding on terrestrial insects living on a husk (or troglobitic insects that are feeding on the husk) carried in by another animal."
(Troglobitic refers to small cave-dwelling animals that have adapted to their dark surroundings)

"This shell was found a couple hundred feet inside the cave in a narrow belly crawl passage. You can use the approximate size of the shell to determine the size of the tiny fruiting bodies.  I think the pictures are fascinating but my actual motivation for passing this along is hopefully there may be someone who might be able to help me identify this specimen. So far it's been a shot in the dark, maybe someone can shed a little light on this - no pun intended."

Since this was in a protected research cave, George needed to leave it untouched.  He sent it to the rest of the Master Naturalists and we sent it around to several people to get an ID.  Mark Bower, a Bull Creek amateur mycologist and photographer, whose books on Bull Creek Fungi I-III many of you have seen, has identified it as Hymenoscyphus fructigenus.

A great web site for any fungus is mushroomexpert.com. Michael Kuo's description* fits George's specimen perfectly.

"This tiny cup fungus competes with Bisporella citrina for the honor of being the smallest mushroom treated at MushroomExpert.Com, with caps maxing out at 4 mm. Growing in clusters on beech nuts, hickory shells, and acorns, Hymenoscyphus fructigenus is often found fruiting alongside Mycena luteopallens--a tiny gilled mushroom that seems enormous by comparison, since a single hickory shell can hold dozens of specimens of Hymenoscyphus fructigenus."

You can read more about this at "mushroomexpert.com. *Kuo, M. (2004, February). Hymenoscyphus fructigenus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/hymenoscyphus_fructigenus.html