Scarletina bolete or Inkstain bolete

The cap of the scarletina bolete is large and fleshy, reaching 5 to 20 centimeters across. When young it is neatly hemispherical, opening with maturity to convex and cushion-shaped. The cap surface is dry and velvety-felty to the touch, and may become slightly sticky in wet weather. The color ranges from warm chestnut and dark brown to yellowish brown, often with a faint reddish or olive tint. When pressed, the cap surface darkens, developing bluish spots.

The cap of the inkstain bolete is small, usually 3 to 10 centimeters across. When young it is convex and hemispherical, opening with age to cushion-shaped and almost flat. The cap surface is dry and velvety-felty to the touch, and in mature mushrooms it may develop fine cracks. The color is dark and rich — from chestnut brown and chocolate to olive-brown, sometimes with yellowish tones. Its most striking trait is the instant reaction to touch: at the slightest pressure, the cap surface immediately floods with dark blue, almost black.

Under the cap lies a tubular hymenophore with a very characteristic, warning feature — the pores here are a rich orange-red, sometimes even blood-red, while the tubes themselves stay yellow or olive-yellow. It's these red pores that make the mushroom look like poisonous species, so it calls for special care. The most important diagnostic trait is the instant, dramatic reaction to touch: just run a finger over the pores, and they immediately flood with a deep dark blue, almost inky color.

Under the cap lies a tubular hymenophore with small pores that are bright yellow or golden yellow when young, turning olive-yellow as they mature. But the hymenophore's main feature is its lightning-fast and extremely vivid reaction: just touch the pores, and in an instant they flood with a deep ink-blue, almost black color. In the intensity and speed of this bluing, the inkstain bolete outdoes practically every other bolete in our forests.

The stem of the scarletina bolete is sturdy, dense and massive, 5 to 15 centimeters tall, often thickened toward the base. It's the stem that gave the mushroom its Ukrainian scientific and folk names: against a yellow-orange background, it is densely covered in tiny reddish and brown scale-like dots that feel like a grainy surface. Unlike its close relative the lurid bolete, the scarletina bolete has no net pattern — just this characteristic grainy "dusting". When touched, the stem turns blue just as quickly. There is no ring and no volva.

The stem of the inkstain bolete is thinner and slimmer than the cap, 4 to 9 centimeters tall, cylindrical or slightly tapering toward the base. It is yellowish at the top and takes on reddish-brown or rusty tones toward the base. There is no net pattern on the stem — its surface is smooth or faintly fibrous. Like the rest of the mushroom, the stem turns blue instantly and intensely when touched or pressed. There is no ring and no volva at all.

The flesh of the scarletina bolete is thick, dense and springy, lemon yellow in a fresh cut. Its main feature is a lightning-fast reaction to air: as soon as you cut the mushroom, the flesh floods before your eyes with an intense dark blue, almost inky color, spreading from the edges to the center. This reaction is so fast and vivid that it's one of the most reliable features of the species. Near the base of the stem the flesh may have a reddish tint. Raw flesh tastes mild, with no bitterness, but you shouldn't taste it raw.

The flesh of the inkstain bolete is yellowish, fairly soft and thin, especially in the stem. Its defining feature is the fastest and most vivid bluing of any bolete: as soon as the mushroom is cut, the flesh literally within seconds floods with a thick dark blue, almost inky color across the whole cut surface. This reaction is spectacular but perfectly safe. The flesh tastes mild and pleasant, with no bitterness, but because of its high arsenic content, it's best not eaten.

The smell of the scarletina bolete is faint, pleasant and typically mushroomy, with no sharp or unpleasant notes. It carries no warning at all and may well seem appealing, so when identifying this species, rely first and foremost on the pore color and the bluing reaction, not on the aroma.

The smell of the inkstain bolete is faint, mild and typically mushroomy, with no sharp or unpleasant notes. The aroma is not a defining feature of the species, so when identifying it, rely first and foremost on the dark velvety cap and the extraordinarily fast and intense bluing of every part of the mushroom.