Honey Fungus or Deadly Galerina? The Spore Print Decides

This is the pairing where "small brown mushroom growing on wood" stops being a shrug.

Galerina marginata contains the same amatoxins as a death cap. It grows on rotting wood and bark mulch, it is common, it is small enough to be overlooked, and it appears alongside honey fungus in the same places at the same time of year.

The spore print separates them, and nothing visible on the fresh mushroom does so reliably.

The spore print

Honey fungus — white.

Deadly galerina — rusty brown.

This is the test. It takes a few hours: cap on paper, covered with a bowl, left overnight, and the colour read against both white and dark paper. How to take a spore print has the method.

Nothing else here is as reliable.

What agrees with it

Hygrophanous is worth knowing: the cap changes colour markedly as it dries, from a dark tawny brown to a much paler tan, often in a band as the drying front moves across. It is characteristic of the galerina and confusing if you do not expect it, because a group of them can look like several different species.

Gill colour is the useful supporting character. Galerina gills mature to rusty brown, matching the spores. Honey fungus gills stay pale. But a young specimen of either has pale gills, which is exactly when people pick them.

Honey fungus itself

Armillaria is edible when thoroughly cooked, and it is not a beginner's mushroom.

• It causes gastric upset in a substantial minority of people even when correctly identified and properly cooked.
• It must never be eaten raw.
• Individual sensitivity varies, so a first try should be a small amount.

It is also a serious pathogen of trees rather than a harmless decomposer — it kills living trees and spreads through the soil by black shoestring-like rhizomorphs, which can be found under the bark of an infected trunk and are diagnostic for the genus.

Finding it on a living tree in your garden is a tree health problem before it is a foraging opportunity.

Deadly galerina

Small, brown, unassuming, and it contains amatoxins.

The course of poisoning is the same as a death cap's: six to twelve hours of nothing, then severe gastrointestinal illness, then an apparent recovery, then liver failure — the pattern in why the delay matters, and set out in full in the death cap.

It grows on:

• Rotting conifer and hardwood logs and stumps
• Bark and wood-chip mulch, which is why it appears in gardens and landscaped beds
• Buried wood, where it looks as though it is growing from soil

The mulch habit is the reason it matters outside foraging. It is a small brown mushroom that turns up in a garden bed where children play, which is one of the specific things to be scanning for after rain.

It has also been mistaken for Psilocybe species by people foraging for those, and that confusion has caused deaths.

The rule this pairing establishes

Small brown mushrooms are the hardest group in the whole subject, and this is the pair that demonstrates why. They require a spore print, and frequently microscopy, and there is no field character that settles them.

Which makes the practical position straightforward: unless you can print the spores and are confident in the genus, small brown mushrooms on wood are not food. Not honey fungus, not oysters, not anything.

The tests that work elsewhere — the gill peel for chanterelles, the cut for morels — have no equivalent here.