Butyriboletus regius

Butyriboletus regius, commonly known as the Royal Bolete, is a species of mushroom belonging to the Boletaceae family. This fungus is notable for its striking appearance, with a vibrant red to purple cap and a yellow to olive stipe (stem), which can catch the eye of mushroom enthusiasts and foragers alike. The pores beneath the cap are typically yellow and can bruise to a blue color when damaged. It is found in woodlands, particularly in association with oak trees, across various parts of Europe and has been reported in some regions of North America.

Description

The cap of Butyriboletus regius can reach up to 15 cm in diameter and is characterized by its rich, red to purple color. The surface of the cap is smooth and can become sticky to the touch in humid conditions. The pores on the underside of the cap are initially yellow and become more olive in color with age. When bruised or cut, the pores quickly turn a blue color, a common trait among many boletes.

The stipe of the mushroom is robust, often bulbous at the base, and displays a net-like pattern, known as reticulation, which is more pronounced towards the top. The stipe's color ranges from yellow at the top to a deeper red or purple towards the base, complementing the cap color.

Butyriboletus regius produces a spore print that is olive-brown in color. The spores are fusiform (spindle-shaped) and smooth.

Habitat and Distribution

Butyriboletus regius is primarily found in deciduous forests, with a particular affinity for oak trees. It forms mycorrhizal associations with these trees, a symbiotic relationship where the fungus exchanges nutrients with the tree roots. This species is predominantly found in Europe, from the British Isles across to the Caucasus region. There have been unconfirmed reports of Butyriboletus regius in North America, but these sightings are rare and may represent misidentifications or introductions.

Edibility

The Royal Bolete is considered edible and is highly prized in some cultures for its taste. However, as with all wild mushrooms, caution is advised when foraging, as it can be confused with other less palatable or even poisonous boletes. Proper identification is crucial to ensure safety.

Conservation

While Butyriboletus regius is not currently listed as endangered, its reliance on specific tree species for mycorrhizal relationships makes it susceptible to changes in forest composition and health. Conservation of its woodland habitats is essential for the continued survival of this species.

See Also

• Boletaceae
• Mycorrhiza
• Edible mushrooms