Cornflower bolete or Brown birch bolete

Cap 5–15 cm, hemispherical in young mushrooms, then cushion-shaped, almost flat in old ones. Color cream, pale yellow, ochre-yellow, darkening with age to brownish yellow. Surface matte, slightly felty or finely cracked in dry weather. The cap skin does not peel. Turns blue instantly when pressed.

Cap 5–15 cm across, at first spherical or hemispherical, later cushion-shaped. The surface is smooth or slightly wrinkled, dry or a little sticky in wet weather. Color ranges from grayish brown to dark brown, more rarely almost black.

Hymenophore tubular, white at first, then yellowish, straw-yellow in mature mushrooms. Pores small and round. When pressed they quickly turn blue, then black — one of the key diagnostic features of the species.

The hymenophore is tubular. The tubes and pores are white, small in young mushrooms and wider in mature ones. When pressed, the pores turn slightly brownish, but there's never any bluing: unlike in the red-capped scaber stalks, the flesh doesn't blue even at the stem base.

Stem 3–12 cm tall, 1–3 cm thick, cylindrical or slightly swollen at the base. Same color as the cap or a little paler. Smooth at the top, sometimes with barely visible veins lower down. In young mushrooms the stem is solid; in mature ones it has hollow chambers inside (also a diagnostic feature of the genus Gyroporus). Quickly turns blue when cut or touched.

Stem 8–18 cm tall, 1.5–3 cm thick, cylindrical, fairly long and slender compared with the cap. The surface is white or grayish, densely covered with dark, fibrous scales — the hallmark of the genus Leccinum. The stem is firm and fibrous.

Flesh white or cream, brittle and fragile, chambered in the stem of mature mushrooms. Exposed to air, within 2–5 seconds it turns a vivid blue, cornflower color — the fastest reaction of any bolete. After a few minutes the blue fades to grayish blue.

The flesh is firm and white; when cut it doesn't change colour or turns slightly pinkish, and after a few hours may become a little greyish or brownish. It darkens to grey-black only when cooked. The taste is mild and neutral. The cap skin doesn't peel.

Smell faint, pleasantly mushroomy, with a note of fresh hazelnut. Taste mild, with no bitterness or spicy notes.

The smell is unobtrusive, pleasant and typically mushroomy. The aroma intensifies with cooking. When dried, the brown birch bolete takes on a rich scent that falls short of porcini but is noticeably better than most other pored mushrooms.