Blueing Reaction
Definition
The blue bruising visible when fresh Psilocybe tissue is cut or damaged, caused by the rapid oxidation of psilocin to a mixture of psilocin-derived oligomers, primarily quinoid psilocyl dimers. Used as a macroscopic screening test; its absence does not exclude psilocybin-containing species.
- Trigger
- Cutting or bruising fresh Psilocybe tissue
- Cause
- Oxidation of psilocin to quinoid psilocyl dimers
- Use
- Macroscopic screening test for psilocybin-containing species
- Limitation
- Absence of blueing does not exclude psilocybin content
Common questions
Why can't the blueing reaction alone confirm a mushroom is psilocybin-containing?+
Blueing is only a presumptive field indicator, and its intensity varies with tissue age, handling, and species. Because a negative or weak reaction can occur even in a species that does contain psilocybin, confirmatory chemical testing such as chromatography is needed before drawing an evidentiary conclusion.
Does every species that shows a blueing reaction contain psilocybin?+
No, blueing itself only demonstrates the presence of oxidisable psilocin-related compounds and is used as a screening cue rather than definitive proof. Some non-psilocybin fungi can show superficially similar bruising, which is why laboratory confirmation remains necessary for identification.
Related terms
- Anomocytic Stomata
- A stomatal type where the guard cells are surrounded by ordinary epidermal cells with no defined subsidiary cells. Found in Erythroxylum and...
- Cathinone
- The natural beta-ketoamphetamine alkaloid from Catha edulis (khat) plant; the parent scaffold for the synthetic cathinone NPS class. The ketone group at...
- Laticifer
- A specialised plant cell or tube system that produces and stores latex, the milky exudate of opium poppy. Laticifers are visible in...
- Ligule (Coca)
- A paired membranous flap at the junction of the leaf blade and petiole unique to Erythroxylum. Its presence in intact dried coca...
- Testa
- The seed coat, derived from the integuments of the ovule. Its surface sculpture (smooth, reticulate, foveolate, echinate, and so on) is a...