Tapinella atrotomentosa

Scientific name: Tapinella atrotomentosa (Batsch) Sutara  
Derivation of name:  Atr- means "black" and toment-
means "wool" or "hair." Atrotomentosus refers to the black,
densely hairy stipe so characteristic of this species.
Synonyms: Paxillus atrotomentosus (Batsch) Fr.,
Agaricus atrotomentosus Batsch  
Common name(s):  Velvet Paxillus; Velvet-footed Pax.
Phylum:   Basidiomycota
Order:   Boletales
Family:   Tapinellaceae
Occurrence on wood substrate: Saprobic; solitary to
several to clustered on conifer stumps, logs, or buried wood;
July through October.   
Dimensions:  Caps 4-15 cm wide; stipes 2-12.5 cm long
and  1-3 cm thick.  
Cap:  Dry, covered with matted hairs; brownish; margin
inrolled when young.      
Gills: Attached to decurrent; yellowish; forked or porelike
near stalk.
Spore print:Yellowish.
Stipe: Eccentric to nearly lateral; velvety with dark brown to
blackish-brown hairs.
Veil: Absent.
Comments:  The blackish-brown wooly stipe distinguishes
this mushroom from other species of Paxillus.

More information at MushroomExpert.com:   

    
Figure 1. Velvet Paxillus on wood. Note the inrolled cap
margin on the youngest specimen.
Photo © William Roody.

Figure 2. Young specimens. Note the decurrent gills and
small size of the cap relative to the stalk. Photo © Pam
Kaminski.

Figure 3. Specimens as they might show up during a
foray. Unless noted while collecting, the association of
the mushrooms with a wood substrate will not be
evident with specimens collected in this manner.
Photo © Gary Emberger.

Figure 4. Portion of the densely hairy stipe just below
the gills. Photo © Gary Emberger.

Figure 5. Forked gills near the stipe. Photo © Gary
Emberger.