Slippery jack or Bay bolete

Cap 4–12 cm across, convex in young mushrooms, later flattened-convex. The surface is covered with a thick layer of slime — especially in wet weather. Color chocolate-brown or chestnut, yellowish brown when dry. The margin often bears remnants of the partial veil.

Cap 5-15 cm across, hemispherical with an inrolled margin when young, later becoming convex-flat. Color chestnut-brown, dark chestnut, honey-brown: the rich color of autumn chestnuts. Darker when young, paler with age. Surface smooth, slightly velvety when young, a little tacky in wet weather, dry and matte in dry weather. The cap skin doesn't peel.

The hymenophore has tubes. Pores yellow, small, regular, turning yellow-green with age. The tubes are attached to the stem or run slightly down it. When pressed, the pores turn slightly brownish.

Tubular hymenophore: the tubes are attached to the stem or slightly notched. Color yellowish when young, turning yellow-olive with age. The pores bruise distinctly blue to blue-green when pressed, a characteristic feature of the species. Spore print olive-brown.

Stem 5–10 cm tall, 1–2 cm thick, solid, cylindrical. Yellow and granular in the upper part, brown or violet-brownish below the ring. A characteristic purple-brown membranous ring — a remnant of the partial veil and one of the key diagnostic features of the species.

Stem 5-10 cm tall, 1.5-3 cm thick, thick, meaty, cylindrical, often thickened toward the base. Color yellow-brown to yellow-ochre, reddish toward the base, with fine lengthwise brownish fibers (not a net like porcini's; this is the key difference). When cut, it bruises faintly blue.

Flesh yellowish or pale cream, firm in young mushrooms, softer in mature ones. Turns slightly pink when cut or stays unchanged. The taste is mild, pleasant, slightly sourish. The cap skin peels off easily together with the slime.

Flesh firm, meaty, white to pale yellow. When cut, it bruises blue slowly and faintly (within 1-2 min, not very noticeably), then fades. Smell and taste pleasant and mushroomy, with a hint of fresh nuts.

Smell pleasant, unobtrusively mushroomy, slightly resinous — reflecting its symbiosis with pine. With cooking the aroma intensifies and becomes more pronounced. No foreign unpleasant notes.

Pleasant, rich, mushroomy, with a hint of nuts and damp forest.