Spore prints
Free, slow, and it settles arguments.
A spore print costs a sheet of paper and a night, and it decides several of the deadly pairs outright: the honey mushroom against the deadly galerina, the parasol against the green-spored one. It takes time, which is exactly why people skip it, and skipping it is how the galerina kills experienced foragers.
The method
- 01Pick a mature specimen. A young cap may not have released spores yet, and a decayed one gives a smeared result.
- 02Cut the stem off flush with the cap so the cap sits flat.
- 03Place it gills or pores DOWN on a sheet that is half white paper and half dark. Colour is the whole point, and pale spores vanish on white while dark spores vanish on black.
- 04Cover with a bowl or a glass. This stops draughts moving the spores and stops the cap drying out.
- 05Leave it two to twelve hours. Overnight is easiest and never a mistake.
- 06Lift the cap straight up and read the colour in daylight, not under a warm bulb, which shifts cream toward yellow and rust toward brown.
Reading the colour
Each colour below lists the species on this site that give it, so a print can be taken straight to a specimen sheet rather than to a guess.
White to cream
Amanita, Armillaria, Pleurotus, Russula, Lactarius, Macrolepiota
Includes both excellent edibles and the deadliest genus there is. A white print rules a great deal IN, which is why it must never be treated as reassurance on its own.
Pink to salmon
Pluteus, Entoloma, Volvariella
Entoloma contains several serious gastrointestinal poisoners, and pink-spored mushrooms are a group beginners should generally leave alone.
Brown to rust
Agaricus (dark chocolate), Galerina and Cortinarius (rusty)
The rusty-brown print is what separates the deadly Galerina from the honey mushroom it grows beside. This one test has saved lives.
Black to purple-black
Coprinus, Panaeolus, Psathyrella
Inky caps digest themselves into black liquid, so take the print early or you will get a puddle rather than a pattern.
Green
Chlorophyllum molybdites, essentially alone
Effectively diagnostic. A green print means the most commonly eaten poisonous mushroom in North America, and nothing else you are likely to meet.
Yellow to ochre
Some Bolbitius, Gymnopilus, certain boletes
Uncommon and easily confused with pale cream under poor light, which is why prints are taken on both white and dark paper.
A spore print narrows things down. It does not confirm a species on its own, and a white print in particular covers both excellent edibles and the deadliest genus there is.