Boletus edulis
The king bolete is the king of mushrooms both by its appearance and by its nutritional properties – its hard hazelnut-flavoured flesh is rich in protein and some B vitamins and minerals.
King boletes can fall prey to a parasitic fungus called bolete eater. Such mushrooms should not be consumed. A mushroom infected with the bolete eater becomes covered with a white mold-like layer, which then turns golden and ultimately reddish-brown.
King bolete hunting pays off best in spruce or mixed spruce forests: the king bolete forms mycorrhizas mainly with the spruce but also with some other trees.
Soft and wormy old king boletes are inedible but they are excellent dye mushrooms. The tube layer on the underside of the cap gives yarn various shades of green and yellow.