Spore colour and spore shape are two of the most reliable clues in mushroom identification. They will not give you a name by themselves, but they let you rule out whole groups of species very quickly.
Safety first: never eat a wild mushroom because a spore print or a microscope looks right. Several deadly species look like edible ones. Identification needs several features checked together, ideally with an experienced local forager or a field guide, and when in doubt you do not eat it.
How to take a spore print
- Pick a mature, fully opened cap and cut off the stem.
- Place the cap gill-side (or pore-side) down on a sheet of paper, half white and half dark, or on a glass slide. Using both backgrounds lets you see pale and dark prints.
- Cover the cap with a bowl or glass so draughts do not disturb it.
- Leave it for 2 to 12 hours. Overnight works for most mushrooms.
- Lift the cap carefully. The pattern left behind is your print.
What the colour tells you
Spore prints range from white and cream through pink, rust and brown to purple-brown and black. This matters because whole groups are separated by it. For example, the deadly death cap (Amanita phalloides) leaves a white print, and the deadly Galerina marginata leaves a rusty-brown one. A colour that rules out the species you hoped for is just as useful as a match.
What a microscope adds
Under a microscope, spores differ in length and width, in overall shape (round, oval, almond, lemon-shaped), in surface texture (smooth or ornamented) and sometimes in features such as a germ pore. Experts record these together. You need at least 400x, and 1000x for surface detail; read our magnification guide.
- Scrape a little of the print into a drop of water on a slide (full method).
- Measure at least twenty spores with a calibrated eyepiece scale.
- Record the range (for example 8 to 11 by 5 to 6 microns) and the shape, and compare against a reputable field guide or species description.
Keeping good records
Note the date, location, habitat, what the mushroom was growing on, cap, gill and stem features and a photo. A spore print without those notes is much less useful than one with them.
If you want reference material to practise on, our spore syringes give you labelled, known samples to compare. Stock up on slides and cover slips too.
Our spore syringes are sold for microscopy and research only. Growing mushrooms that contain psilocybin is illegal in the UK. This guide is general information, not legal advice. You must be 18 or over to buy from this shop.
