Summary:
Distinctive field characters are the large irregular pores and the black layer separating the upper tomentum from the lower flesh. These together distinguish it from other Datronia spp. in the Pacific Northwest. Other features include a usually shelf-like form, a dark brown concentrically grooved upper surface, and a pore surface that is buff to umber brown with angular to maze-like pores.

Microscopic:
spores 10-12 x 3-4.5 microns, cylindric, smooth, inamyloid, colorless; basidia 4-spored, 30-45 x 5-6.5 microns, clavate, with a narrow base, with basal clamp; cystidioles imbedded or slightly projecting, 25-45 x 4-5 microns, fusoid, thin-walled, with basal clamp, dendrohyphidia present on dissepiment edges, 1.5-3 microns wide, branched and contorted; hyphal system dimitic: context generative hyphae 2.5-4 microns wide, thin-walled, nodose-septate, context skeletal hyphae "thick-walled, aseptate, those in lower context pale greenish-brown in KOH, those in upper dark layer darker brown in KOH, some with frequent branching, 2.5-4 microns in diam", trama hyphae similar to those in lower context, (Gilbertson), spores 8-10.5 x 3.5-4 microns, cylindric-elliptic, smooth, inamyloid, colorless, some with drops, (Breitenbach)

Spore Deposit:
white (Buczacki)

Notes:
Datronia mollis has been found in BC, WA, OR, ID, NS, ON, PQ, AK, CO, IA, IL, IN, KY, ME, MI, MN, MT, NH, NY, OH, PA, TN, VA, VT, WI, WV, and WY, (Gilbertson).

EDIBILITY

no (Phillips)

Synonyms and Alternate Names:
Daedalea mollis Sommerf.: Fr.
Hydnum underwoodii (Banker) D. Hall
Sarcodon underwoodii Banker