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Blue Roundhead

Inedible Inedible
Autumn Autumn
Winter Winter

Not a poisonous mushroom but can cause gastric upsets.

Mushroom Type
Common Names Blue Roundhead (EN), Pengrwn Glas (CY), Pierścieniak Niebieskawy (PL), Zöldeskék Harmatgomba (HU)
Scientific Name Stropharia caerulea
Season Start Aug
Season End Dec
Average Mushroom height (CM) 9
Average Cap width (CM) 8
Please note that each and every mushroom you come across may vary in appearance to these photos.


Convex opening to flattened cone. Green/blue when young turning pale tan/green.


White turning grey/brown. Not crowded.


White turning pale blue. Covered in scales.


Has a long-lasting white ring, the top surface of which becomes coloured with the brown spores.


White/pale blue.


Mixed woodland, heath and grassland.

Possible Confusion

The only similar looking mushroom is the Verdigris Agaric (Stropharia aeruginosa), which is rarer and has white edged gills.

Spore Print

Purple/brown. Ellipsoid. The spores should be scrapped into a small pile to get an accurate spore colour.


Fairly common.

Other Facts

This mushroom suspected to contains psilocybin and psilocin, powerful hallucinogens. There is a single study back from 1981 which reported these substances from the fruit body of S. caerulea, but it seems to be just a mistake, because none of the later analytical studies were able to find any of these even in traces.
This mushroom will also cause gastric upsets so is not a safe mushroom for consumption.


9 comments for Blue Roundhead

  1. Carol Barac says:

    I have found these in my garden, should I report them?

  2. Yage says:

    For trespassing in their natural habitat?

  3. Chris says:

    Hahaha, you should pick them and make spore prints. Perhaps you could do something else with them if you so chose….

    But thats a hilarious comment haha, call the authorities some mushrooms are growing hahahahahaha so funny 🤣

  4. My size Baby cakes says:

    Please could you Send them my way please it would be much appreciate for mycology purposes of course x kind regards T

    1. Sam says:

      Hey can we make contact

  5. Heather says:

    Hi I found this mushroom on my allotment it is blue / green in colour and slimy is it a bad one

    1. Eric Biggane says:

      It could be a Blue Roundhead but we would need to see photos of the cap, stem and gills to be sure.

  6. Jackie Hammond says:

    Cortinaius Rotunisporus are growing in Port Stephens on the East Coast. Report of blue wide tops after rain for over two week .

    1. Attila Fodi says:

      Hi Jackie,
      Thank you for your comment. We are a UK-based company, and we don’t really have much information about Australian and New Zealand fungi. Cortinarius rotundisporus is native to Australia, but documented from New Zealand too, and it is mycorrhizal with Eucalyptus and Leptospermum species, so you can separate the two species by their habitat. When we mention potential lookalikes, they are mostly from the UK or from other parts of Europe (in case of polypores I might have more information about lookalikes from different continents, so I might add them in our online Mushroom Guide). Anyway, thank you for the info, it is indeed a beautiful blue mushroom.

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