Hapalopilus nidulans

Scientific name:   Hapalopilus nidulans (Fr.) Karst.
Derivation of name:   Hapalopilus means "with a soft tender
pileus or cap"; nidulans means "nesting or lying in a cavity."
Synonymy:   Polyporus nidulans Fr.
Common names:   Tender nesting polypore.
Phylum:   Basidiomycota
Order:   Polyporales
Family:   Hapalopilaceae
Occurrence on wood substrate: Saprobic; solitary, grouped,
or in overlapping clusters on decaying deciduous (rarely
conifer) wood; June through November.   
Dimensions:  Caps up to 12 cm wide and 2.5 cm thick.   
Upper surface:  Brownish-orange to cinnamon-brown; with
matted hairs, becoming glabrous; one or more concentric
furrows.
Pore surface: Yellowish to cinnamon-brown; 2-4 pores per
mm.
Edibility: Inedible.
Comments: All parts turn purple with KOH.
 
More information at MushroomExpert.com:   

    
Figure 1. Sessile brackets of Hapalopilus nidulans. These
brackets are soft and watery when fresh. Photo © John
Plischke III.

Figure 2. Pore surface of Tender nesting polypore.
Photo © Tom Volk.

Figure 3. The purple discoloration on the cap is from the
application of KOH. Photo © Tom Volk.