How to identify a mushroom from a photo: five steps from the underside to the lookalikes

“What mushroom is this?” is probably the most common question after a walk in the woods. You want to snap your find and get a name in a second. But a photo isn’t an answer, it’s a set of clues. What matters is the order you read them in: from the most reliable features to the least.

Below are the five steps experienced foragers use. Our mushroom identifier follows the same path: it asks about features in exactly this order. All the photos in this article are our own.

Step 1. Look under the cap

Cap colour is the most misleading feature: it fades in the sun, darkens after rain, and in a single species can range from yellow to brown. So the first thing to check is what’s under the cap. There are only a few options:

• gills — thin plates running from the stem to the edge, as in brittlegills, field mushrooms and amanitas;
• tubes with pores — a “sponge”, as in the porcini, birch bolete or slippery jack;
• ridges — thick, forked “veins” running down the stem, as in the chanterelle;
• spines — as in the hedgehog mushroom.

In this photo is a brittlegill: even cream gills and a white stem with no ring. Below are two birch boletes: one shows its cap from above, the other its pale pores from below.

This one step rules out most of the catalogue. A photo that doesn’t show the underside is almost impossible to identify. More on the difference in our article on boletes and gilled mushrooms, and on all the parts of a mushroom in mushroom anatomy in photos.

Step 2. Look for amanita signs: a ring and a sac

If there are gills under the cap, the next question is about safety. The most dangerous mushrooms in our forests, the death cap and its amanita relatives, share a telling set of features: white gills, a skirt-like ring on the stem and a sac (volva) at the base.

A ring is easy to see in a photo, as on this fly agaric. The volva is trickier: it often hides in the leaf litter, and if the mushroom was cut with a knife, it won’t be in the photo at all. Here’s a tawny grisette: it has no ring, but its stem rises from a white sac. It’s an amanita too.

The rule is simple: if you see white gills together with a ring or a sac, the mushroom doesn’t go in the basket, whatever the photo suggests. And if the base isn’t in the picture, nobody can honestly rule out a death cap.

Step 3. The cut, the colour and the smell

The third step is what a single shot of the cap can’t show: the colour of the flesh when cut, and the smell. Many boletes turn blue, red or yellow when cut, and that’s often what separates similar species.

In the inkstain bolete, the cut stem turns ink-blue almost instantly, and that reaction is how it’s recognised. But bluing is a clue to the species, not a toxicity test. We explained why in our article on why boletes turn blue when cut.

A smell can’t be photographed, so write it down: mealy, aniseed, radish-like, unpleasant or none. The identifier has a separate field for it.

Step 4. Where and when it grew

Many mushrooms live in partnership with particular trees. The birch bolete grows with birch, the slippery jack with pine, and the oak bolete mostly under oaks. So the trees nearby often narrow the choice more than any detail of the cap.

This birch bolete was growing among heather and birch leaves, and the place tells you as much as its scaly stem. The substrate (soil, moss, a stump, twigs) and the month matter just as much: you won’t find spring morels in autumn, and a mushroom calendar helps you see what’s growing now.

Step 5. Compare with the lookalikes

When you’re down to two or three candidates, the most useful thing is to put them side by side and find the feature that tells them apart. The classic example is the bitter bolete, often mistaken for the porcini.

From above they look alike, but the underside shows what matters: the bitter bolete’s pores are pinkish, while the porcini’s start white and turn yellow-olive. We’ve collected differences like these on our comparison pages, for example porcini vs bitter bolete.

Why AI won’t do this for you

Apps that “identify mushrooms from a photo” see colour and shape, but not the smell, the cut or the sac in the soil. In 2023, Australian toxicologists tested three popular apps on photos of mushrooms people had actually been poisoned by. The best one named only 49% of the mushrooms and 44% of the poisonous ones correctly, and one app recognised the death cap in just 27% of cases. The researchers concluded that such apps alone aren’t reliable enough to rule out a poisonous mushroom.

So an app can be a hint about where to start, but not an answer. More on this in our article Mushroom ID apps: can you trust them?.

How to follow these steps in the MycoNote identifier

Our identifier is built on exactly this logic. You add up to three photos (the cap, the underside, the base of the stem) and mark what you see: what’s under the cap, a ring, a sac, the colour when cut, the smell, the trees nearby, the place and the date. Don’t know a feature? Just say so.

The site then suggests similar species from the catalogue and shows honestly how many features match. If a poisonous species even roughly fits the description, it comes first. Then other foragers see your find: they vote for a species and leave comments. When at least five people and two thirds of the votes agree on one species, the find is marked “Confirmed”. It’s free and works in your phone’s browser. Step by step in the identifier guide.

When a photo will never be enough

Some mushrooms can’t be identified from a photo by anyone: small brown gilled mushrooms, webcaps, many brittlegills. They’re told apart by microscopic features, chemical reactions or a taste test that only specialists do. The honest answer for them is “to genus”, and that’s enough reason to leave them be.

And most importantly: an identification from a photo is a guess, not a green light. Even “Confirmed” in the identifier only means most foragers agreed on the species. A mushroom identified only from a picture doesn’t go in the basket. And if someone has already eaten a doubtful mushroom and feels unwell, call 112 — read about the first signs in our article on mushroom poisoning.