Psilocybe semilanceata (Liberty Cap)
A plain-language profile of Psilocybe semilanceata, the liberty cap: its scientific name and synonyms, what is known about its chemistry, documented harms, and why names and photos are not safety assurances.
Content last updated . This page has not been medically reviewed.
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Documented analytical data
Each group below is one study's measurement of the stated specimen or preparation. It is not a typical value for the species or product, varies between specimens, and says nothing about effects or safety. 10 values from 1 source.
Gotvaldova K, Borovicka J, Hajkova K, Cihlarova P, Rockefeller A, Kuchar M. Extensive Collection of Psychotropic Mush... (10 values)
Source: Gotvaldova K, Borovicka J, Hajkova K, Cihlarova P, Rockefeller A, Kuchar M. Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids. Int J Mol Sci 2022;23:14068. doi:10.3390/ijms232214068. Read 2026-10-22. Laboratory: not stated in the excerpt read (authors Gotvaldova, Kuchar et al.; UHPLC-MS/MS Agilent 1290/6460). Method: UHPLC-MS/MS (Agilent 1290 Infinity + 6460 triple quad, C18), methanol/0.5% acetic acid extraction. Date: not reported in source (as read).
| Specimen or preparation | Analyte | Value | What it is | Sample size and scope |
|---|---|---|---|---|
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | aeruginascin | 0.01 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | lowest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | aeruginascin | 0.033 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | highest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | baeocystin | 0.725 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | lowest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | baeocystin | 4.467 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | highest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | norbaeocystin | 0.121 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | lowest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | norbaeocystin | 0.51 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | highest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | psilocin | 0.033 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | lowest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | psilocin | 0.619 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | highest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | psilocybin | 1.28 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | lowest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
| Psilocybe semilanceata, wild-collected fruiting bodies (as named in source) | psilocybin | 11.421 mg/g (dry weight (whole fruiting bodies, cap + stipe; dried at no more than about 40 C by collectors)) | highest value of range (reported) | 18 fruiting bodies / 5 collections. range across 18 fruiting bodies from 5 collection(s) (whole fruiting bodies, individual-specimen values; no mean reported) |
Safety first
If someone has eaten a wild or unknown mushroom, or a child has eaten any mushroom, call US Poison Help at 1-800-222-1222, or 911 in an emergency. See poisoning: what to do first. This page is education only. It gives no way to find, identify or use this fungus.What it is
Psilocybe semilanceata is a fungus in the family Hymenogastraceae. The accepted name is Psilocybe semilanceata (Fr.) P.Kumm., first published in 1871 under that combination. [1] The database lists many older synonyms, including Agaricus semilanceatus, Panaeolus semilanceatus and Stropharia semilanceata. [2] "Liberty cap" is a common English name. Common names can be shared or used loosely, so only the scientific name is reliable.The compound it contains is covered in the psilocybin guide.
Why it is discussed in Europe
A Danish review noted that this species was the most common psilocybin-containing wild mushroom in Denmark, and anticipated rising use as an intoxicant based on experience in the USA and western Europe. [3] That is a 1990 observation from one country, not a current survey.What has been measured
A 2015 chemistry paper reported that P. semilanceata contains comparatively high amounts of psilocybin (around 1% of dry weight) and some baeocystin, with psilocin only in traces. [4] The same paper tabulated results from several earlier studies, and the reported ranges differ widely. So treat any single figure as one measurement of particular specimens, not a typical value for the species. A 2022 study of museum specimens found psilocybin and psilocin decay over time in a species-dependent way and that some old specimens had none detectable. [5]A 2025 report presented a draft genome for the species, which helps scientists study how the fungus makes its compounds. [6]
What research shows in people
Label: insufficient evidence. Proper evidence not found for clinical trials of this mushroom as a treatment. We searched PubMed under the species name. Clinical research uses isolated psilocybin; see psychedelic clinical trials and their limits.Documented harms
Case reports cannot show how common a harm is, but they show what can happen.- A series from a toxicology department in Kraków described four people who used the species for hallucinations; one had an exogenous psychosis, and the others were observed in the emergency department. Symptoms resolved in about 6 hours without organ damage. [7]
- A 2022 case report from Aberdeen, UK, described takotsubo cardiomyopathy (a temporary heart muscle weakness) after recreational ingestion, and said it was the second such case the authors found. [8]
- The Danish review warns that more dangerous mushrooms can be eaten by mistake when identification is wrong. [3]
Naming
A 2022 DNA study reported that museum specimen names are largely unreliable apart from a few well-known species. [5] See why photos and names are not safety assurances and commercial mushroom names.Legal status
Not verified on this page. Laws differ by country and change; see psychedelic legal status by country. This is not legal advice.Related guides
Compare with Psilocybe cubensis or browse the Psilocybe species directory.Frequently asked questions
What is a liberty cap?
It is a common name for Psilocybe semilanceata. [1]
Has it been shown to treat any condition?
Proper evidence not found. Clinical research uses isolated psilocybin, not this mushroom.
Can eating it cause heart problems?
One case report links ingestion to takotsubo cardiomyopathy. One case cannot show how often this occurs. [8]
Is it safe to identify from a picture?
No. Misidentification is a recognized hazard. [3][5]
References
- GBIF Secretariat. GBIF Backbone Taxonomy record: Psilocybe semilanceata (Fr.) P.Kumm., accepted. Read 2026-10-22.
- GBIF Secretariat. GBIF synonyms of Psilocybe semilanceata. Read 2026-10-22.
- Lassen JF et al. Hallucinogenic psilocybine containing mushrooms. Toxins contained in Danish wild mushrooms. Ugeskr Laeger 1990 (Danish; English abstract). Read 2026-10-22.
- Gartz J, Wiedemann G. Discovery of a new caerulescent Psilocybe mushroom in Germany: Psilocybe germanica sp.nov. Drug Test Anal 2015. Read 2026-10-22.
- Bradshaw AJ et al. DNA Authentication and Chemical Analysis of Psilocybe Mushrooms Reveal Widespread Misdeterminations in Fungaria and Inconsistencies in Metabolites. Appl Environ Microbiol 2022. Read 2026-10-22.
- Bollinger IM et al. High-quality draft genomes of ecologically and geographically diverse Psilocybe species. Microbiol Resour Announc 2025. Read 2026-10-22.
- Satora L et al. Poisonings resulting from the ingestion of magic mushrooms in Kraków. Przegl Lek 2005. Read 2026-10-22.
- Kotts WJ et al. Psilocybin-induced takotsubo cardiomyopathy. BMJ Case Rep 2022. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.