Leratiomyces ceres, commonly known as the Redlead Roundhead, is mushroom which has a bright red to orange cap and dark purple-brown spore deposit. It is usually found growing gregariously on wood chips and is one of the most common and most distinctive mushrooms found in that habitat. It is common on wood chips and lawns in North America, Europe, Australia, New Zealand and elsewhere. The name Stropharia aurantiaca has been used extensively but incorrectly for this mushroom (together with a number of similar synonyms).
(Cooke & Masee) Spooner & Bridge (2008)
Agaricus squamosus f. aurantiacus sensu auct.
|gills on hymenium|
|cap is convex|
|hymenium is adnate|
|stipe has a ring|
|spore print is brown|
|ecology is saprotrophic|
- Cap: 2 to 6 cm in diameter, with thin flesh and a bright red to orange top which is convex to plane in age. Has white partial veil remnants when young. The cap surface is usually dry, but can be slightly viscid when moist.
- Gills: White to pale grey at first, later darker purple/brown or purplish grey with whitish edges. Attached (adnexed to adnate) and often notched.
- Stipe: Whitish, often with dark orange stains in age (most evident around base), 3–6 cm long and 0.5 to 1 cm wide, equal to slightly larger at the base, which often has mycelium attached. The veil is thin and leaves a fragile, indistinct ring, sometimes missing with age. The stalk is smooth above the ring zone and is fluffy with tiny scales below, which often wash off in rain.
- Spores: Dark purple/brown. 10–13.5 × 6–8.5 m. Elliptical and smooth.
- Other microscopic features: Chrysocystidia are present both on the edges and on the faces of the gills.
- Taste and odor: Mild
- Edibility: Edible, at least when cooked.
There has been some confusion between L. ceres, which has a fairly thick white stem, and L. squamosus var. thaustus, which has a slender stem and prominent scales below the ring zone (although the two taxa are quite easy to distinguish by sight). Around 1885 Mordecai Cubitt Cooke originated the names Agaricus squamosus f. aurantiacus and Agaricus thraustus var. aurantiacus, and this later gave rise to the name Stropharia aurantiaca. This name is defined by Cooke's illustration to his Handbook of British Fungi and in 2004 Richard Fortey discovered that this illustration was not of L. ceres, as had generally been assumed, but it was L. squamosus var. thaustus. Thus the name aurantiaca is best avoided, being wrong when applied to L. ceres.
In psilocybin mushroom hunting communities in Australia and New Zealand, L. ceres (or "Larrys" as commonly nicknamed) are scorned as lookalikes and imposters of Psilocybe species on wood chip. Prolific growth in the same habitats and a similar appearance from afar can give false hope of a large bounty, but on closer inspection the species are not particularly alike.
- Bridge PD, Spooner BM, Beever RE, Park DC. (2008). Taxonomy of the fungus commonly known as Stropharia aurantiaca, with new combinations in Leratiomyces. Mycotaxon 103:109–121.
- Arora D. 1986. Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi (2nd edition). Berkeley: Ten Speed Press. ISBN 0-89815-169-4.
- Eyssartier, G.; Roux, P. (2013). Le guide des champignons France et Europe (in French). Belin. ISBN 978-2-7011-8289-6. L. ceres is on p. 834 and L. squamosus var. thaustus on p. 814.
- Knudsen, H.; Vesterholt, J., eds. (2018). Funga Nordica Agaricoid, boletoid, clavarioid, cyphelloid and gasteroid genera. Copenhagen: Nordsvamp. p. 947–8. ISBN 978-87-983961-3-0.
- Davis, R. Michael; Sommer, Robert; Menge, John A. (2012). Field Guide to Mushrooms of Western North America. Berkeley: University of California Press. pp. 218–219. ISBN 978-0-520-95360-4. OCLC 797915861.
- Trudell, Steve; Ammirati, Joe (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. p. 211. ISBN 978-0-88192-935-5.
- "Psilocybe aurantiaca page". Species Fungorum. Royal Botanic Gardens Kew. Retrieved 2019-12-12.
- Fortey, Richard (2004). "Psilocybe aurantiaca: and a case of mistaken identity". Field Mycology. 5 (3): 77–80. doi:10.1016/S1468-1641(10)60555-5.
- "Leratiomyces ceres page". Species Fungorum. Royal Botanic Gardens Kew. Retrieved 2019-12-12.