Caesar's mushroom

Appearance

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 or rarely 20 cm in diameter. The free gills are pale to golden yellow, as is the cylinder-shaped stipe, which is 8–15 cm tall and 2–3 c 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.

It could be confused with the poisonous fly agaric. 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 rather than a yellow stalk and is typically associated with spruce, pine or birch. Certain varieties are close to yellow even at the juvenile stage.

Naming

"Amanita caesarea" was first described by Italian mycologist Giovanni Antonio Scopoli in 1772 as "Agaricus caesareus", before later being placed in "Amanita" by Persoon in 1801. The common name comes from its being a favourite of the Roman emperors, who took the name Caesar as a title. It was a personal favorite of Roman emperor Claudius. The Romans called it "Bōlētus", derived from the Ancient Greek βωλιτης for this fungus as named by Galen. 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", due to its resemblance to an egg when very young. In Albanian it is "kuqëlorja" from its colour. 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 Sikkim, India. It is widely eaten in the Himalayas and the Tibetan areas. Also North American collections have been labeled in the past as "A. hemibapha". 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 similar mushroom can also be found in La Esperanza, Honduras, where a festival is celebrated annually in its honor. "A. caesarea" was first domesticated in 1984.

Distribution

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. The mushroom is also distributed in the Balkans, Hungary, India, and China. Although the species is not known to exist in the United States and Canada, it has been collected in Mexico.

In Europe, "Amanita caesarea" inhabits primarily oak forests. 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 above sea level, where it prefers plains and can occur at slopes of 20 degrees.