Tyromyces chioneus

Scientific name:   Tyromyces chioneus (Fr.) P. Karst.
Derivation of name:   Tyromyces means "with a cheesy
consistency"; chioneus means "snow white" in reference to the
color of this polypore.
Synonymy:   Polyporus chioneus Fr.; Polyporus albellus
Peck; Tyromyces albellus (Peck.) Bondartsev & Singer.
Common names:   White cheese polypore.
Phylum:   Basidiomycota
Order:   Polyporales
Family:   Polyporaceae
Occurrence on wood substrate:  Saprobic; solitary or
grouped, sometimes overlapping or fused on decaying
deciduous wood; July through December. 
Dimensions:  Caps 2-10 cm wide and up to 2 cm thick.   
Upper surface: White to grayish; azonate; finely hairy to
glabrous as it matures.
Pore surface: Whitish; pores 3-5 per mm.
Comments: When fresh, this polypore feels soft and watery.
In fact, droplets of water are easily squeezed out of it. The
polypore has a fragrant odor when fresh. A similar species,
Tyromyces galactinus, typically has a distinctly tomentose
upper surface. The two species also differ in the reaction of
the cap surface and flesh to KOH: T. galactinus turning
yellow and T. chioneus not turning yellow.   

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Figure 1. Tyromyces chioneus on a hardwood branch.
Photo© Dianna Smith.

Figure 2. The fruit bodies of Tyromyces chioneus are
rather featureless to the eye. All surfaces are white and the
pores are so small they initially appear nonexistent. Their
soft, watery texture and pleasant aroma require the use of
senses other than sight. Photo © John Plischke III.

Figure 3. Tyromyces chioneus is full of water when fresh.
Photo © David Work.