King Bolete – Boletus edulis

King Boletes are among the most prized of edible fungi of Europe

Common Name: King Bolete, Cep (French), Porcino (Italian), Steinpilz (German), White Mushroom Белый Гриб (Russian; pronounced “belly greeb”) – The reference to regality conveys the notion that this mushroom is the king, as it is widely considered from the Epicurean European perspective, the epitome of the genus Boletus. It is described by David Arora in Mushrooms Demystified as “… magnificent – a consummate creation … the one aristocrat the peasantry can eat.”

Scientific Name: Boletus edulis – Traditionally, the genus name is attributed to the Latin word for mushroom, boletus, which is in turn derived from the Greek βωλίτηζ (originating from βωλοζ, which means ‘lump’). However, some philologists believe that there is an association between mushroom names and place names. From this perspective, the genus was named for the town Boletum located in Hispania Tarraconnensis, the Roman province comprising northern Spain. Whether this is a toponym, the town being named for the mushroom, or vice versa, will likely never be resolved. The specific edulis means “eatable” in Latin.

Potpourri: King Boletes are among the most prized of edible fungi of Europe, second only to truffles in gustatory appeal. They are characterized by large reddish-brown, smooth caps that are viscid when wet and that have white pores on the underside that become tawny with age. The stalk is probably the most notable feature; it is stout and tends to be bulbous with white reticulations, a webbed or netted pattern of raised striae that extend over the upper portion. They are generally found singly or in small groups under conifer trees, notably spruce and hemlock, and some deciduous trees, notably birch. They are mycorrhizal in their association, providing water and minerals to the tree roots in exchange for the tree’s photosynthetic glucose for nutrition.

The Boletus edulis look-alike is  the aptly named Bitter Bolete (Tylopilus felleus

Identification of the King Bolete is not a trivial matter, as they are quite variable in the coloration and diameter of the cap and in the girth of the stipe or stem. According to Charles McIlvaine, describing the mushroom in the seminal One Thousand American Fungi, “some species appear to have that prize of Fairyland – the Wishing Cap – and by its power be able to take on any form they please.” There is some indication that B. edulis is actually a group of related species and that the variants found in North America are not the same as those found in Europe, where they were first described. However, they are gathered assiduously for consumption across the globe, a fact that attests to the facility that most people have in identification once some experience with the species is gained. Another factor that allows for some lassitude is that there are no known deadly boletes and the ones that cause adverse reactions, notably gastric distress, can be readily distinguished be a simple test. The aphorism among mycophagists is that you can eat any bolete except those that have red gills, those that stain blue, or those that taste bitter. This latter feature distinguishes the King Bolete’s most common look-alike, the aptly named Bitter Bolete (Tylopilus felleus).

The proliferation of the names for B. edulis is distinguished not so much by its global reach as by its rich diversity in etymology. It is the opinion of David Arora in Mushrooms Demystified that, “…it has more common names than there are languages.” This suggests that the mushroom was independently identified, consumed and named in separate, disconnected regions with different cultural traditions. It was among the first mushrooms to be described, the French Botanist Pierre Buillard establishing it as a unique plant (fungi were thought to be plants in the Phylum Thallophyta until well into the 20th Century) in 1782. It was the first mushroom of the genus Boletus to be named, and is therefore considered the Boletus ‘type’ species. It was a well-known edible at that time, as Buillard describes it in his Herbier de la France as “très agreeable au gout, et à l’odorat, on le mange à toute saufse (sic)” (very agreeable to taste and smell, one can eat it in total safety). Given this paean to its gustatory attributes relative to the low risk of adverse effects in one of the first field guide publications, it is not surprising that it was widely consumed and popularly known by different common names.

In Western Europe, the common names of Boletus edulis are generally derived from a similarity in appearance between one of the mushroom’s attributes and a physical object. In England, it is called the ‘Penny Bun’ due to the rounded shape and brown color of the cap. To the Germans, it is the ‘Steinpilz’ or ‘stone mushroom’ which may refer to either the firmness of the mushroom or to the fact that it looks like a smooth riverbed stone. The French common name ‘Cep’ or ‘Cepe’ has a more labored etymology; ‘Cep’ is the Gascon word for ‘tree trunk’ which comes from the Latin cippus meaning ‘stake’ (and ‘tombstone’ with some unintended irony for a choice edible mushroom). The likely reference is to the bulbous and trunk-like stalk, the mushrooms most notable feature. The most ubiquitous of the Western European names is porcino which is Italian for ‘little pig, as this is the name which is most frequently used in the extensive B. edulis export market trade; the label ‘porcini’ (plural) is quite frequently seen in the produce sections of food markets. The metaphorical comparison to piglets which is probably both for appearance and taste, reflects the earlier Roman tradition of referring to a bolete-type mushroom as Suillus, the word for ‘swine’ (the name survives as the genus Suillus, a group of mushrooms with pores  like those of the genus Boletus).

In Eastern Europe, Boletus edulis is afforded a much more honored position in the culinary pantheon, and it is accordingly referred to in terms that reflect its singular munificence. In Poland, it is known as Prawdziwek, literally ‘true mushroom,’ a designation that has extends to the Balkans as Pravivrganj with the same meaning. But it is in Russia that the esteem reaches the pinnacle of the natural cuisine. The Белый Гриб or ‘white mushroom’ is considered ambrosial, the name conveying not only the color of the flesh and pore surface, but also the purity of the fungus in comparison to the ‘black mushroom,’ considered of inferior quality. According to the noted Russian author Vladimir Nabokov, it has “that special boletic reek which makes a Russian’s nostrils dilate – a dark, dank satisfying blend of damp moss, rich earth and rotting leaves.” The Russian Wikipedia website lists 20 different regional names that range from the pedestrian ‘boletus’ (боровик) to the more anthropomorphic ‘grandma’ (ба́бка). Traditionally, the white mushroom is collected in Autumn and dried or pickled in brine for later consumption.

The King Bolete is highly nutritious, with significant amounts of protein and amino acids, a fact that is generally not at all appreciated by the general public. A 100 gram serving (3.5 ounces) contains over 7 grams of protein with a fat content of less than 2 grams and a total caloric level of only 82 kilocalories (the vernacular calories are really kilocalories). It is also rich in the B vitamins and in important minerals, especially iron and zinc. However, like most mushrooms, it is comprised primarily of carbohydrates, about 65 percent of the total dry weight, mostly in the form of chitin, a polysaccharide that is not digestible by humans and accordingly passes through the intestinal tract as beneficent dietary fiber. Chitin is the fundamental cellular structure of all mushrooms (plants cells are cellulose) which accounts for their ‘meat-like’ texture. But perhaps to most notable of nutritional attributes of B. edulis is its amino acid composition; it contains all eight of the essential amino acids. A good source of protein must have all of these essential amino acids or it must be part of a balanced diet that does; any deficiency in one results in a reduction in the synthesis of the other seven. Shu-Ting Chang and Phillip Miles rank foods according to their essential amino acids in relation to adult dietary requirements in a quantitative index on a scale of 0 to 100 in Mushrooms, Cultivation, Nutritional Value, Medicinal Effect, and Environmental Impact. Mushrooms (98) rank just below meat (100) and above spinach (76).