Pileus 30-100 mm in diameter, conic to convex, expanding to broadly convex and eventually flattening with age with a pronounced, persistent broad umbo; surface smooth, viscous when moist, covered by a separable gelatinous pellicle; chestnut to ochraceous brown to caramel in color often becoming pitted with dark blue or bluish black zones, hygrophanous, fading to light straw color in drying, strongly bruising blue when damaged; margin even, sometimes irregular and eroded at maturity, slightly incurved at first, soon decurved, flattening with maturity, translucent striate and often leaving a fibrillose annular zone in the upper regions of the stem. Lamellae ascending, sinuate to adnate, brown, often stained info-black where injured, close, with two tiers of lamellulae, mottled, edges withish. Spore-print dark purplish brown to purplish black in mass. Stipe 90-200 mm long by 3-6 mm thick, silky white, dingy brown from the base or in age, hollow at maturity. Composed of twisted, cartilaginous tissue. Base of stem thickening downwards, often curved, and characterized by coarse white aerial tufts of mycelium, often with azure tones. Mycelium surrounding stipe base densely rhizomorphic (i.e., root-like), silky white, tenaciously holding the wood-chips together, strongly bruising bluish upon disturbance. They have no odor to slightly farinaceous. Their taste is extremely bitter.