Hat diameter from 35 to 150 mm. Cream-colored, straw-yellow or with an ocher shade, at the touch points changing the color of the ink-blue. In the shape initially hemispherical, later convex, with age slightly flattened. Matte surface, covered with fine hairy fibers, fibrous, rough to the touch. The shore is rolled up for a long time, the tubes protrude slightly.

Tubes 3 to 8 mm long, whitish, creamy or pale yellowish, damaged immediately blue, near the stem almost free or sinuate.

Small, round or wide - oval pores, white, age yellowish, blue when touched.

Stem length from 50 to 120 mm and thickness from 10 to 30 mm. The color of the hat, at the top lighter, after breaking, quickly changing the color to ink-blue. On the surface slightly branched to felted, in the upper part with a small thickening, above which is smooth. Irregularly cylindrical or at the base, they have thickened. From the outside it was hard and brittle, at first full, then weathered, finally divided by empty chambers.

Firm pulp, firm and fragile. White or light cream color, after damage on the entire surface (hat, tubes, backbone) changing the color to ink-blue (rarely not dyeing: var. Lacteus), then brightening, taking on a dirty-gray-white color. The aroma is slight, the taste is mild, pleasant. Dried or heat-treated takes on a golden-yellow color, with the exception of tubes that are olive-brown.

Occurrence: In deciduous and coniferous forests, under oaks, birches, pines, especially on sandy soils. In some regions of Poland frequent, in others it is rare. From June to October.

Value: edible.