Deadly fibrecapInocybe erubescens

YES — it's one of the few truly deadly species in the genus Inocybe. Fatal cases among healthy adults have been documented in Europe. Do not pick it in any form, under any circumstances. The temptation to "just have a taste", or mistaking it for an Agaricus, can cost you your life.

Within 15-60 minutes — sudden profuse salivation (by the liter), sweating through your clothes, tearing, runny nose, a feeling of suffocation, slow heartbeat down to 30-40 bpm, a drop in blood pressure, stomach cramps, diarrhea. In severe cases — collapse and a risk of cardiac arrest. Call immediately 112 or your local emergency number — don't wait in the hope that "it'll pass". In hospital you'll be given atropine. Put any leftover mushrooms in a bag — it's critical for the doctor to know exactly what was eaten. Do NOT treat yourself with atropine — in the wrong dose it is lethal.

Three critical differences. (1) Flesh when cut: in Inocybe erubescens it slowly turns red gradually, sometimes only after 30 min or more (especially in the lower part of the stem). In a young Agaricus it either doesn't change color or turns yellow. (2) Gills: in Inocybe — whitish at first, then olive-brown. In Agaricus — pink at first, then chocolate-brown and almost black. (3) Spore print: in Inocybe — olive-brown. In Agaricus — blackish-brown. Before eating, you must cut a young mushroom in half and wait at least 30 minutes — if the flesh starts turning red, don't eat it. But this test is not a green light: if the flesh doesn't redden, that doesn't make the mushroom safe, and some edible Agaricus species (such as the blushing wood mushroom, Agaricus silvaticus) redden too. Identify by all the features together — gills, spore print — and when in doubt, leave it.

In broadleaf and mixed forests under oak, beech, hornbeam and hazel. It loves limestone and alkaline soils. It often grows in grassy spots, at forest edges, and in gardens and parks with old broadleaf trees. It forms mycorrhiza, so it's tied to specific trees.

The Carpathians, the Carpathian foothills, the Western and Right-Bank Forest-Steppe (especially on the limestone soils of Podillia), and less often Polissia. In the steppe — in parks and ravine woodlands. The species isn't common, but it's found regularly.

May — August, peaking in June–July. This coincides with the season for spring edibles (St George's mushroom, early Agaricus), which makes the risk of confusion even greater.

With young field mushrooms (Agaricus) — the most common and most fatal mix-up. With St George's mushroom (Calocybe gambosa) — also a whitish spring mushroom. With Shield pinkgill — also white and springtime. The general rule: never pick a white or cream forest mushroom without checking the flesh for reddening + taking a spore print. If the flesh turns red (wait at least 30 min) — absolutely do not eat it.

YES — it's the only well-known Inocybe with a white/cream cap that turns red. Other poisonous fibrecaps usually have a brown or yellowish cap from the very start. Reddening white cap + sweetish, fruity smell + olive-brown spore print = I. erubescens, the most dangerous of them all.