Mycology safety guide

Conocybe filaris: The Deadly Psilocybin Look-Alike

The other deadly amatoxin psilocybin look-alike — a small lawn-and-mulch mushroom that carries the same toxin as the death cap. Species ID, spore print, and poisoning timeline.

What is Conocybe filaris?

Conocybe filaris is a small, deadly poisonous mushroom found on lawns, mossy ground, and wood-chip mulch. It carries the same amatoxins that make the death cap lethal. Mycologists now usually file it under the name Pholiotina rugosa (it has also been called Pholiotina filaris), but the older name Conocybe filaris is still the one most people search for.

The species fruits from late summer through autumn across the Pacific Northwest, temperate North America, and Europe. It favours cool, damp conditions and appears in exactly the kind of grassy, well-watered ground where lawn-loving Psilocybe species also grow. That habitat overlap is the whole danger: a person hunting small brown "magic mushrooms" in a field can pick this one by mistake.

Why it matters: the amatoxin problem

Conocybe filaris produces alpha-amanitin, the same peptide toxin found in the death cap and in Galerina. The toxin binds RNA polymerase II inside liver cells and shuts down protein synthesis, so the cells die slowly over several days. That delay is what makes amatoxin poisoning so dangerous — by the time a person feels genuinely ill, the liver is already under attack.

The clinical picture is identical to any amatoxin exposure. For the full timeline and what emergency teams actually do, see our amanitin poisoning guide.

Identifying features

Cap

The cap is small, roughly 0.5 to 2.5 centimetres wide. It starts conic or bell-shaped and stays fairly narrow, sometimes flattening a little with age. Colour is cinnamon to tawny-brown, often paler at the margin. The surface can look finely wrinkled toward the centre, which is the trait behind the name rugosa ("wrinkled").

Gills

Gills are close, attached to the stem, and rust-brown to cinnamon in mature caps because they carry rust-coloured spores. Younger caps show paler, more yellow-brown gills before the spores mature.

Ring on the stem — a warning flag

Conocybe filaris is one of the few small lawn mushrooms with a distinct ring on the stem. The ring is membranous and can slide or fall, and it is often dusted rust-brown from falling spores. Most true Conocybe have no ring at all, so a small brown lawn mushroom that does have one deserves extra caution — not less. The ring alone is never a safety test, but it is a feature people fixate on and misread.

Stem and bruising

The stem is thin, pale brownish, and finely powdered or lined, usually 2 to 8 centimetres tall. It does not bruise blue. This matters because the lawn and grassland Psilocybe species people confuse it with — such as Psilocybe semilanceata (the liberty cap) — tend to bruise a bluish colour when handled or damaged. Absence of blueing does not prove a mushroom is safe, but its presence points away from Conocybe.

Spore print — the diagnostic feature

Take a cap, remove the stem, and set the cap gill-side-down on white paper for two to four hours. Conocybe filaris drops a rust-brown to cinnamon spore print. Every Psilocybe species drops a purple-black to dark violet-brown print. This is the single most reliable field test, and it is why the North American Mycological Association (NAMA) tells foragers never to eat any small brown mushroom whose spore print they have not taken.

Habitat

Look for it on lawns, in mossy turf, along path edges, and in wood-chip mulch and garden beds — usually growing scattered or in small groups rather than tight clusters on logs. This grassy, disturbed-ground habitat is shared with lawn-inhabiting psilocybin species, which is why the two are found in the same places.

Look-alike confusion: Conocybe filaris vs Psilocybe

Small, brown, grassland mushrooms are the exact profile of several psilocybin species — especially Psilocybe semilanceata (liberty cap) in pastures and lawns. The overall size and colour overlap closely enough that a hurried forager can grab the wrong mushroom. The differences that actually matter are the spore print and the blue-bruise reaction, not cap shape. See also:

FeatureConocybe filarisPsilocybe (lawn/grassland group)
Spore printRust-brown to cinnamonPurple-black to violet-brown
Blueing when handledNoneOften bruises bluish on stem or damage
Ring on stemPresent, membranous, may slide or fallUsually absent; when present is a fragile veil remnant
Gill colour (mature)Rust-brown to cinnamonDark purple-brown to nearly black
HabitatLawns, moss, wood chipsGrass and pasture — direct overlap
Growth habitScattered or small groupsScattered in grass

Conocybe filaris vs Galerina marginata

Conocybe filaris and Galerina marginata are the two amatoxin mushrooms most often flagged as deadly psilocybin look-alikes. They share the same toxin and the same emergency response, but they favour different ground: Galerina grows in tight clusters on rotting wood, while Conocybe filaris is a lawn-and-mulch mushroom that grows scattered in grass. Knowing which habitat you were picking in helps identifiers, but neither distinction is a safety test.

FeatureConocybe filarisGalerina marginata
Typical habitatLawns, moss, wood chips (grassy ground)Rotting wood, logs, mulch (clusters)
Growth habitScattered or small groupsTight clusters on wood
CapSmall, conic, cinnamon, wrinkled centreSmall, convex-flattening, honey to tawny
Spore printRust-brown to cinnamonRusty brown
ToxinAlpha-amanitinAlpha-amanitin
Poisoning courseBiphasic, 6–24h onsetBiphasic, 6–24h onset — same picture

Documented poisonings

Conocybe filaris is a recognised cause of amatoxin poisoning in North America and Europe, and mushroom-poisoning references list it alongside Galerina and Amanita among the small brown mushrooms responsible for serious cases. Poison-control and mycological sources — including the NAMA mushroom-poisoning syndromes summary and annual data from the American Association of Poison Control Centers — group amatoxin exposures together because the clinical management is the same regardless of which species was eaten. The recurring theme in case reports is misidentification of a small brown lawn mushroom as an edible or psychoactive species.

What to do if you may have eaten Conocybe filaris

  1. Call US Poison Help at 1-800-222-1222 immediately, even if you feel fine.
  2. Save any leftover mushrooms, spore prints, or vomit in a sealed bag — the poison centre or hospital will use this for identification.
  3. Photograph the picking site if you can — habitat, substrate, and growth habit help mycologist consultants.
  4. Go to the emergency department. Say "possible amatoxin poisoning" — that phrase tells the ED to run liver function tests immediately and to consider activated charcoal and IV fluids before symptoms start.
  5. Do not induce vomiting on your own. Do not "wait to see if symptoms develop." The 6–24 hour silent window is when treatment works best.

The legal alternative to foraging

If your interest is a psilocybin experience, wild foraging is not the safer route — even where possession has been decriminalized. Oregon's Measure 109 service centers and Colorado's Prop 122 healing centers exist precisely so adults can access dose-verified, professionally identified psilocybin without picking mushrooms. See:

Frequently asked questions

Is Conocybe filaris poisonous?

Yes — it is deadly. Conocybe filaris (Pholiotina rugosa) contains alpha-amanitin, the same amatoxin as the death cap and Galerina marginata. There is no safe amount, and cooking or drying does not make it safe. Any suspected ingestion is a medical emergency.

Is Conocybe filaris a psychedelic mushroom?

No. Conocybe filaris does not contain psilocybin and produces no psychedelic effect. It is a toxic look-alike that grows in the same grassy habitat as some psilocybin species, which is why foragers confuse the two. Eating it causes amatoxin poisoning, not a trip.

How do I tell Conocybe filaris from a Psilocybe?

Take a spore print and check for blue bruising. Conocybe filaris drops a rust-brown to cinnamon spore print and does not bruise blue. Psilocybe species drop a purple-black print and often bruise bluish. Conocybe filaris also usually has a ring on the stem. None of these alone is a safety guarantee — use all of them, and when unsure, do not eat it.

What is the difference between Conocybe filaris and Pholiotina rugosa?

They are the same mushroom under different names. Molecular and taxonomic work moved the species out of Conocybe, and it is now usually called Pholiotina rugosa (previously Pholiotina filaris). Older field guides and most searches still use "Conocybe filaris."

Can cooking or drying Conocybe filaris remove the poison?

No. Amatoxins are heat-stable, freeze-stable, and dry-stable. They survive cooking, drying, tea preparation, and long-term storage. Every home preparation method that works for other risky foods fails here.

How fast does Conocybe filaris poisoning start?

Symptoms are delayed. Amatoxin poisoning is biphasic: a silent window of roughly 6 to 24 hours, then violent gastrointestinal symptoms, then a deceptive "false recovery," then liver and kidney failure around days 3 to 5. Because the early phase is silent, treatment works best when it starts before symptoms appear — call poison control immediately.

What should I do if my dog ate a Conocybe mushroom in the yard?

Call the ASPCA Animal Poison Control Center at 888-426-4435 or go directly to an emergency vet. Amatoxin poisoning in dogs follows the same biphasic pattern and is fatal without aggressive treatment. Bring a sample of the mushroom if possible.

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Sources

  1. North American Mycological Association. NAMA Toxicology Committee — mushroom poisoning case registry and identification standards. namyco.org. NAMA.
  2. North American Mycological Association. Mushroom poisoning syndromes — amatoxin (amanitin) group. namyco.org. NAMA.
  3. American Association of Poison Control Centers. Annual Reports of the National Poison Data System (NPDS). aapcc.org. AAPCC.
  4. ASPCA Animal Poison Control Center. Mushroom toxicity in companion animals. aspca.org. ASPCA.