The pileus of this species is viscid with black virgate fibrils radiating to the margin over an obscure yellow ground color. The yellow colors are also present on the lamellae and at the stipe apex. The odor and taste are farinaceous. The specimen illustrated came from the Talamancas under Quercus costaricensis at 3000 m elevation. Prior to 1998, the specimen illustrated was thought to be T. sejunctum, but after consultation with M. Christensen (Denmark), there is every indication that the heavy dark fibrils on pileus point to T. portentosum. See his web page for illustrations of European Tricholomas.