Porcini or Lurid bolete

Cap 7–30 cm across, spherical or hemispherical in young mushrooms, becoming cushion-shaped and spread out over time. The color varies from light brown to dark chestnut or reddish brown depending on light and forest type: caps are darker in spruce woods and lighter in pine forests.

The cap surface is dry, smooth or slightly wrinkled, and can be a little sticky in wet weather. The margin is even or slightly wavy, inrolled in young mushrooms. The skin doesn't peel.

The cap of the lurid bolete is large and fleshy, reaching 8 to 20 centimeters across. When young it is hemispherical, becoming convex and cushion-shaped with age. The cap surface is dry, finely velvety or felty to the touch, and slightly greasy-shiny in wet weather. The color is warm and variable — from olive-yellowish and gray-brown to ochre-brown and clay-colored, often with a pinkish sheen. When pressed, the cap surface darkens and develops blue-green spots, which instantly gives away the nature of this mushroom.

The hymenophore is tubular and separates easily from the cap flesh. In young mushrooms the tubes are white, later turning yellow; in mature ones they're yellow-green or olive. The pores are small, round, uniform in color and don't change color when pressed.

Under the cap lies a tubular hymenophore with bright, rich orange-red or blood-red pores that contrast sharply with the yellowish-olive tubes. It's these red pores that put the lurid bolete in the group of "dangerous-looking" boletes. At the slightest touch the pores instantly turn blue, flooding with a dark blue color. A characteristic microscopic feature of the species is a thin reddish layer between the tubes and the cap flesh, visible in a lengthwise cut.

Stem massive, 5–20 cm tall and 3–10 cm thick, bulbous or club-shaped in young mushrooms, later cylindrical. Color from whitish to light brown. The surface is covered with a characteristic white or cream net pattern, most distinct in the upper part of the stem.

There's no ring and no volva. The base of the stem is often thickened.

The stem of the lurid bolete is sturdy and massive, 8 to 15 centimeters tall, noticeably thickened or club-shaped and swollen at the base. Its main diagnostic feature is a distinct net pattern: a raised reddish net stands out clearly against a yellow-orange background, covering almost the entire surface of the stem. It's this red net that reliably distinguishes the lurid bolete from the scarletina bolete, whose stem is covered in separate dots rather than a net. When touched, the stem quickly turns blue. There is no ring and no volva.

The flesh is dense, juicy and white, and doesn't change color when cut or damaged — this feature sets porcini apart from a number of poisonous lookalikes. In old fruiting bodies the flesh becomes spongy and yellowish.

The taste is mild, nutty and slightly sweet. The stem flesh is denser and more fibrous than the cap flesh.

The flesh of the lurid bolete is thick, dense and fleshy, lemon yellow in a fresh cut, and often wine-reddish near the base of the stem. Its most striking trait is rapid, vivid bluing on exposure to air: as soon as the mushroom is cut, the flesh floods with a thick dark blue color within seconds. This dramatic reaction is typical of the species and helps with identification. Raw flesh tastes mild, with no bitterness, but you absolutely should not taste it raw, because the uncooked mushroom is toxic.

The smell is pleasant, unobtrusive, mushroomy with light nutty notes. With cooking and drying the aroma intensifies and takes on a deep, rich woody, foresty character. It's for dried porcini that the mushroom is so valued in cooking — no other dried mushroom gives such a pronounced taste and smell.

The smell of the lurid bolete is faint, pleasant and gently mushroomy, sometimes with a barely noticeable fruity note. The aroma carries no warning and may even seem appealing, so don't rely on it for identification — the main guides remain the red pores, the red net on the stem and the rapid bluing of the flesh.