Identification
White champignon-like mushroom; the cap and especially the stem base turn bright yellow when cut or pressed; smell phenolic, "chemical". Gills pink → brown.
Why it is dangerous
Gastrointestinal syndrome: vomiting, diarrhea, cramps within 1–2 hours. Sensitivity varies — some people tolerate it, but the species consistently accounts for urban mushroom poisonings.
How not to confuse it
| Feature | Field mushroom | Yellow-stainer |
|---|---|---|
| Cut flesh | whitish, maybe slightly pink | instantly bright yellow |
| Smell | mushroomy, anise | phenolic, inky |
| Habitat | meadows, forest edges | lawns, gardens, city soil |