(excerpt from Vinalhaven Sightings Report)
Split Gill (Schizophyllum commune)
"Schizoid" might be a little exaggeration but this fungus definitely has a mix of characteristics not normally found together in the fungal world. The “split” gills are actually adjacent plates covered with the fungus' spore producing layer, like a polypore. When wet, the plates open to allow for the dispersal of spores, giving the fungus the "split gill" look. In dry weather the plates roll up, thus protecting the spore-bearing surface and giving it a more gilled fungus feel. When dry, the ventral view of a split gill appears to be that of a gilled shroom, but flip them over and the splitting of the gills is evident. Steward Kirk Gentalen has only spotted the split gill twice on Vinalhaven, both times on driftwood newly washed ashore.
For a full report on what is being seen around the island, you can follow the Sightings Report Blog.