Domain: Eukarya
Kingdom: Fungi
Phylum: Basidiomycota
Class: Agaricomycetes
Order: Polyporales
Family: Meripilaceae
Genus: Grifola

Grifola frondosa photo courtesy of MushroomObserver.org, 2008, MushroomObserver.org

Commonly known as Sheep’s Head, Hen of the Woods, or Maitake, Grifola frondosa is an edible species that grows at the foot of trees, particularly oak trees, in clusters of gray-brown caps which are generally curled or contorted in some manner and originate from a single branched stem structure (1), (2), (4).

See Tom Volk’s page on Grifola frondosa

(2)