Edibility

The four-rung ladder

We don't sort mushrooms into 'edible' and 'poisonous'. We sort them into how much certainty you need before they're food. It's a ladder, and you climb it one careful step at a time.

The rungs

1  unmistakable   nothing toxic looks like it
2  learnable      one or two key checks
3  expert-only    needs microscopy or context
4  do not touch   lookalikes can be lethal

The rule

Never eat anything you can't name with your own eyes, hands, and a spore print. If you need the app to be sure, you aren't sure — and that's fine. Walk away and learn it for next time.