St. George's Mushroom

The cap measures from 5–15 cm (2 to 6 inches) in diameter and has a smooth texture with ridges on it. The colour of the cap, stipe and flesh ranges from white to creamy. The sinuate gills are white and crowded. The stubby stipe is bulky at the base. The flesh is dense and soft, with a mealy or cucumber smell. The spore print is white.

Similar species. Care must be taken not to confuse it with the highly poisonous Inosperma erubescens, which grows in the same habitats. The latter has a more pungent fruity smell and bruises red. Entoloma sinuatum, also poisonous, has a rancid smell. Additionally, it may resemble the inedible Melanoleuca strictipes.

Calocybe gambosa is common in grasslands in Europe, often in areas rich in limestone. It is common on the Swedish islands Öland and Gotland, both situated in the Baltic Sea. On the South Downs in southern England, it has formed huge fairy rings that appear to be several hundred years old. It is found from April to June in the United Kingdom, earlier in warmer countries and later in cooler ones. It appears in March in Italy, hence its regional name marzolino (also known as prugnolo).

The mushroom is best picked in dry weather. Although it resembles some poisonous species, it can be eaten cooked, pickled, and evidently raw. The species is imported in commercial quantities from Romania, Hungary, and Turkey. It was held in high esteem in medieval Italy, reported by Costanzo Felici in 1569 as the most expensive and highly regarded mushroom in Umbria and Marches in central Italy. It was also held in high esteem in the Apennine Mountains region—Liguria, Tuscany, and Emilia-Romagna)—by Giovanni Targioni Tozzetti in 1777. It is still locally eaten in Emilia-Romagna and Tuscany. St. George's mushroom is highly prized in the Basque Country of northern Spain, where it fetches very high prices. In Álava, it is traditionally eaten on the feast of Saint Prudentius (28 April), alongside snails. The mushroom is also a cornerstone of the gastronomy of Bilbao, where it is typically eaten in an omelette. The demand in the Basque Country is so high the mushroom has to be imported from Eastern Europe.