Gloeophyllum sepiarium

Scientific name:   Gloeophyllum sepiarium (Fr.) Karst
Derivation of name:  Gloeophyllum means "with glutinous or
sticky leaves"; sepiarium means "dark, sepia-colored."
Synonymy:   Lenzites saepiaria (Wulf. ex Fries) Fries;
Daedalea sepiaria Fr.
Common names:   Yellow-red gill polypore.
Phylum:   Basidiomycota
Order:   Polyporales
Family:   Gloeophyllaceae
Occurrence on wood substrate: Saprobic; solitary or grouped
or in rosette-like clusters most often on dead conifer wood; June
through November, overwinters. 
Dimensions: Caps 2.5-10 cm wide.   
Upper surface: Bright yellowish-red to reddish-brown or
brown with a white to yellow to orange growing margin; hairy to
almost smooth; zonate.  
Pore surface: Golden-brown; mostly gill-like with few pores;
gills 1.5-2 per mm.
Edibility: Inedible.
Comments:  G. trabeum is a similar species but its pore
surface is more a mixture of gills, pores, and maze-like areas. Its
gills are more crowded (2-4 per mm), its pores are smaller (up
to 4 per mm along the margin), it usually grows on deciduous
wood, and it never has the bright colored growing margin that G.
sepiarium has.

More information at RogersMushrooms.com:

 
Figure 1. Note the brownish color with bright yellowish
growing margin. Photo © Larry Grand.

Figure 2. A whitish growing margin and zonate caps. Photo
© Tom Volk.

Figure 3. Specimen with a very dark central area and
bright yellow growing margin. Photo © John Plischke III.

Figure 4. Herbarium specimens.

Figure 5. The gill-like pore surface of this herbarium
specimen of Yellow-red gill polypore is entirely gilled
(lamellate) with no pores or maze-like areas.

Figure 6. Gloeophyllum sepiarium.
Photo © George Barron.