Panellus stipticus (bitter oysterling)

These are a tough little gilled saprophyte that grows singly or in small clusters. They look somewhat like a fruiting of very very small oysters. But, upon closer inspection, they’re actually quite different. Like oysters, they grow in little clusters, are shelf like, and have gills. However, the gills have a clearly defined end point, and they often have short narrow stems which aren’t typically visible from the top. When wet, they are brownish in color and have brownish gills. In the dry winter months they become hard and leathery. The gills will remain brown, but the cap surface often becomes whitish and flaky, with some brown at the margins. Perhaps most interesting is that this mushroom is bioluminescent, although I have not witnessed this yet myself.