Amanita caesarea

Amanita caesarea Scientific classification Kingdom: Fungi Division: Basidiomycota Class: Agaricomycetes Order: Agaricales Family: Amanitaceae Genus: Amanita Species: A. caesarea Binomial name Amanita caesarea (Scop.) Pers. (1801) Synonyms Agaricus caesareus Scop. (1772) Amanita caesarea Mycological characteristics gills on hymenium cap is convex hymenium is free stipe has a ring and volva spore print is white ecology is mycorrhizal edibility: choice but not recommended

Amanita caesarea, commonly known in English as Caesar's mushroom, is a highly regarded edible mushroom in the genus Amanita, native to southern Europe and North Africa. This mushroom was first described by Giovanni Antonio Scopoli in 1772. This mushroom was a favorite of early rulers of the Roman Empire.^[1]

It has a distinctive orange cap, yellow gills and stipe. Organic acids have been isolated from this species. Similar orange-capped species occur in North America and India. It was known to and valued by the Ancient Romans, who called it Boletus, a name now applied to a very different type of fungus.

Taxonomy and naming

Amanita caesarea was first described by Italian mycologist Giovanni Antonio Scopoli in 1772 as Agaricus caesareus,^[2] before later being placed in Amanita by Persoon in 1801.^[3] The common name comes from its being a favourite of the Roman emperors, who took the name Caesar (originally a family name) as a title. It was a personal favorite of Roman emperor Claudius.^[4] The Romans called it Bōlētus, derived from the Ancient Greek βωλιτης for this fungus as named by Galen.^[5] Several modern common names recognise this heritage with the English Caesar's mushroom and royal amanita, French impériale, Polish cesarski and German Kaiserling. In Italian, it is ovolo (pl. ovoli), due to its resemblance to an egg when very young.^[6] In Albanian it is kuqëlorja from its colour (< Albanian kuqe 'red'). Other common names include Amanite des Césars and Oronge.

It has also been classified as A. umbonata. A. hemibapha is a similar species originally described from India, and this name has sometimes been applied to North American collections. The relationship of the similar North American species A. arkansana and A. jacksonii to A. caesarea is not clear. The edibility of some of these similar species is also unclear, though A. jacksonii is eaten by many and there have been no reports of illness from it. A. caesarea was first domesticated in 1984.^[7]

Description

Specimen of A. caesarea

This mushroom has an orange-red cap, initially hemispherical before convex and finally flat. The surface is smooth, and margins striated, and it can reach 15 cm (6 in) or rarely 20 cm (8 in) in diameter. The free gills are pale to golden yellow, as is the cylinder-shaped stipe, which is 8–15 cm (3–6 in) tall and 2–3 cm (around 1 in) wide. The ring hangs loosely and is lined above and smooth below. The base of the stipe is thicker than the top and is seated in a greyish-white cup-like volva, which is a remnant of universal veil. The spores are white.^[8]

It could be confused with the poisonous fly agaric (Amanita muscaria). Though A. muscaria has a distinctive red cap dotted with fluffy white flakes, these tend to fall off as the carpophor ages and the bright red tends to fade to a yellowy orange. The latter mushroom will always have white gills and stalk with a ringed volva^[8] rather than a yellow stalk and is typically associated with spruce (Picea), pine (Pinus) or birch (Betula).^[9] Certain varieties (e.g. Amanita muscaria var. guessowii) are close to yellow even at the juvenile stage.

Chemical properties

Amanita caesarea, young fruit body

A study of isolates from the fruit bodies of A. caesarea showed that the radial growth (increases in axon's diameter) of this species was possible at pH 6-7, and optimal growth was in a temperature of 24–28 °C (75–82 °F), depending on the isolate.^[10]

An investigation of the heavy metal content of mushroom samples found cadmium levels in A. caesarea four times greater than allowed in cultivated mushrooms by EU standards. The amount of lead in A. caesarea also exceeded allowed levels. The study concluded that the accumulation of heavy metals may be a species-specific property of mushrooms, and that chronic consumption of some mushroom types could potentially be harmful.^[11]

A study of the organic acid composition of mushrooms found a relatively high level, about 6 g/kg, in A. caesarea. Malic acid, ascorbic acid, citric acid, ketoglutaric acid, fumaric acid, shikimic  acid and traces of succinic acid were detected. Malic and ascorbic acids were the most abundant compounds.^[12] Ergosterol has also been isolated from A. caesarea.^[13]

Edibility

A. caesarea is good to eat, although it is not recommended because it can be confused with red and orange forms of the poisonous Fly agaric, A. muscaria.

A. caesarea is a highly appreciated mushroom in Europe. It is traditionally gathered and consumed in Italy, where it is known as ovolo or ovolo buono or "fungo reale".^[14] It has been traditionally taken as food in Mexico. There it is consumed roasted with a bit of the herb epazote, Dysphania ambrosioides. The international export market developed in the 1990s.^[15]

Distribution and habitat

A. caesarea specimen from Italy.

It is found in southern Europe and North Africa, particularly in the hills of northern Italy. It is thought to have been introduced north of the Alps by the Roman armies as it is most frequently found along old Roman roads.^[8] The mushroom is also distributed in Balkan paeninsula, Hungary,^[16] India,^[17] and China (Sichuan Province).^[18] Although the species is not known to exist in the United States and Canada, it has been collected in Mexico.^[19][20]

In Europe, Amanita caesarea inhabits primarily oak forests (Quercetum troianae Em. et Ht., Quercetum frainetto-cerris Rudsky. and Quercetum frainetto-cerris macedonicum Oberd., e.g.). It grows individually or in groups from early summer to mid autumn. In warmer climates this mushroom fruits in higher oak woodlands, sometimes mixed with conifers. Thus, in Mexico its natural habitat is oak, pine or fir forests at altitudes of 2,200–3,000 m (7,200–9,800 ft) above sea level, where it prefers plains and can occur at slopes of 20 degrees.^[15]

Amanita caesarea is listed in the Red Data book of Ukraine,^[21] and it is protected by law in Croatia,^[22] and Slovenia.^[23]

See also

• List of Amanita species

References

1. Volk, Tom. "Tom Volk's Fungus of the Month for March 2002". Retrieved 17 November 2012.
2. Scopoli JA. (1772). Flora Carniolica exhibiens Plantas Carnioliae Indigenas et Distributas in Classes, Genera, Species, Varietates ordine Linnaeano. Vol. 2 (in Latin). Vienna: Johann Paul Krauss. p. 419.
3. Persoon CH. (1801). Synopsis Methodica Fungorum (in Latin). Gottingae. p. 252.
4. Marley, Greg A. (2010). Chanterelle dreams, amanita nightmares : the love, lore, and mystique of mushrooms. White River Junction, Vt.: Chelsea Green Pub. p. 112. ISBN 978-1-60358-214-8.
5. Ramsbottom J. (1953). Mushrooms & Toadstools. Collins. p. 6. ISBN 1-870630-09-2.
6. Carluccio A. (2003). The Complete Mushroom Book. Quadrille. pp. 23–24. ISBN 1-84400-040-0.
7. Chang, Philip G. Miles, Shu-Ting (1997). Mushroom biology : concise basics and current developments. Singapore: World Scientific. p. 139. ISBN 981-02-2877-5.
8. Breitenbach J, Kränzlin F (1995). Fungi of Switzerland 4: Agarics, 2nd Part. p. 146. ISBN 3-85604-240-7.
9. Breitenbach J, Kränzlin F (1995). Fungi of Switzerland 4: Agarics, 2nd Part. p. 150. ISBN 3-85604-240-7.
10. Daza, A.; Manjón, J. L.; Camacho, M.; Romero de la Osa, L.; Aguilar, A.; Santamaría, C. (15 November 2005). "Effect of carbon and nitrogen sources, pH and temperature on in vitro culture of several isolates of Amanita caesarea (Scop.:Fr.) Pers.". Mycorrhiza 16 (2): 133–136. doi:10.1007/s00572-005-0025-6.
11. Cocchi, Luigi; Vescovi, Luciano; Petrini, Liliane E.; Petrini, Orlando (2006). "Heavy metals in edible mushrooms in Italy". Food Chemistry 98 (2): 277–284. doi:10.1016/j.foodchem.2005.05.068.
12. Valentão, Patrícia; Lopes, Graciliana; Valente, Miguel; Barbosa, Paula; Andrade, Paula B.; Silva, Branca M.; Baptista, Paula; Seabra, Rosa M. (1 May 2005). "Quantitation of Nine Organic Acids in Wild Mushrooms". Journal of Agricultural and Food Chemistry 53 (9): 3626–3630. doi:10.1021/jf040465z.
13. Yokokawa, H.; Mitsuhashi, T. (1981). "The sterol composition of mushrooms". Phytochemistry 20 (6): 1349–1351. doi:10.1016/0031-9422(81)80036-2.
14. "ovolo". Enciclopedia Treccani. Treccani. Retrieved 28 September 2013.
15. Poe, Melissa Renee (2009). Wild Mushrooms, Forest Governance, and Conflict in the Northern Sierra of Oaxaca. ProQuest. p. 139.
16. Zoltan K. (1986). "Mushrooms Of The Vali Forest Central Hungary". Botanikai Kozlemenyek (in Hungarian) 73 (1–2): 49–72. ISSN 0006-8144.
17. Rishikesh M. (2003). "Some wild edible mushrooms of Siang valley: Arunachal Pradesh.". Plant Archives 3 (1): 81–84. ISSN 0972-5210.
18. WeiHong P, BingCheng G, Wei T, Yong G. (2003). "Studies on economic mushrooms in Longmen mountain areas". Southwest China Journal of Agricultural Sciences (in Chinese) 16 (1): 36–41. ISSN 1001-4829.
19. Castano-Meneses G, Quiroz-Robledo LN. (2004). "Ants (Hymenoptera: Formicidae) associated with macromycetes fungus (Fungi: Basidiomycetes) in sierra de Taxco, Guerrero, Mexico". Folia Entomologica Mexicana 43 (1): 79–86. ISSN 0430-8603.
20. Guzmán G, Ramirez-Guillen F. (2001). The Amanita caesarea-complex. Bibliotheca Mycologica 187 (Berlin: J. Cramer). ISBN 978-3-443-59089-5.
21. Sarkina IS, Prydiuk MP, Heluta VP. (2003). "Macromycetes of Crimea, listed in the red data book of Ukraine". Ukrayins'kyi Botanichnyi Zhurnal 60 (4): 438–46. ISSN 0372-4123.
22. MINISTARSTVO ZAŠTITE OKOLIŠA I PROSTORNOG UREĐENJA
23. Al-Sayegh Petkovsek S, Pokorny B, Piltaver A. (2003). "The first list of macrofungi from the wider area of the Salek Valley". Zbornik Gozdarstva in Lesarstva (in Slovenian) (72): 83–120. ISSN 0351-3114.

External links

• Photos and description of A. caesarea
• Photos and description of related North American species, with some discussion of relationships
• Classification problems of this mushroom
• Amanita caesarea from Portugal with photos and information