Mushroom ID apps: can you trust them?

There are dozens of apps in the App Store and Google Play that “identify mushrooms from a photo”. They’re genuinely convenient: point the camera, get a name. But a name isn’t an answer to the forager’s real question: can this mushroom go in the basket?

How these apps work

A neural network compares your photo with thousands of pictures it was trained on and returns the most similar species. It sees colour, cap shape and sometimes gills or pores. What it can’t see:

• the smell — mealy, aniseed, radish-like — which often decides it;
• the colour when cut and how it changes over a few minutes;
• the base of the stem in the soil — the bulb or sac (volva) that gives deadly amanitas away.

What the study found

In 2023, toxicologists at the Victorian Poisons Information Centre and a mycologist at the Royal Botanic Gardens Victoria (Australia) tested three popular apps. They used photos of 78 mushrooms from real enquiries to the poisons centre and the botanic gardens in 2020–2021. Every mushroom was identified precisely by the mycologist.

Here’s the share of mushrooms each app named correctly:

• Picture Mushroom — 49% of all mushrooms, 44% of poisonous ones, 60% of death caps;
• Mushroom Identificator — 35% of all mushrooms, 30% of poisonous ones, 67% of death caps;
• iNaturalist — 35% of all mushrooms, 40% of poisonous ones and only 27% of death caps.

The sample is small and the apps have been updated since, so the exact numbers may be different today. But the researchers’ conclusion is simple: such apps alone aren’t reliable enough to rule out a poisonous mushroom.

Where an app helps, and where it lets you down

As a hint about where to start, an app is fine: it can suggest a genus or a few similar species to read about. It lets you down exactly where a mistake costs the most: with young mushrooms, lookalikes and photos without the base of the stem. Take the death cap: when young it’s easily confused with a field mushroom or a green brittlegill, and the sac at its base is often not in the photo at all.

How to check what an app suggests

• Open the card of the suggested species and compare the underside, the ring and the stem base, not just the colour.
• See what this species gets confused with: every MycoNote card has a lookalikes section.
• Ask people. In the MycoNote identifier you add photos and features, the site suggests similar species and puts poisonous lookalikes first, and foragers vote for a species. It’s free and works in your phone’s browser.
• Never put a mushroom in the basket on the strength of a photo alone — whether an app or other foragers identified it.

Step by step in our article on how to identify a mushroom from a photo.