Serious
Gastrointestinal irritants
A grab-bag of unrelated compounds, most of them still unidentified
Onset after the meal
30 minutes to 4 hours
Inside six hours, which is the reassuring side of the line, with one qualification: a mixed wild meal can produce an early reaction that hides a late one.
Attacks
The gut lining
What it does
Nausea, forceful and repeated vomiting, cramps and diarrhoea, sometimes bloody. It is genuinely violent and people are frightened by it.
How it runs
Self-limiting, typically over within 24 hours. The real danger is dehydration and electrolyte loss, which is what puts people in hospital, especially children and the elderly.
Treatment
Rehydration, and anti-emetics if needed. Supportive rather than specific.
The catch
This is the most common group by a wide margin, and its speed is the reassuring part. But an early irritant reaction in a MIXED wild meal can hide a late amatoxin one, so a fast onset only rules out the worst if you are certain a single species was eaten.
Species that cause it
This is reference material, not clinical guidance and not a substitute for a poison centre. If somebody is unwell after eating a wild mushroom, call one now, tell them the interval between the meal and the first symptom, and keep an uncooked specimen.