Rubroboletus rubrosanguineus

Description
Mushroom Identification
History
Synonyms

Description

Rubroboletus rubrosanguineus is a species of bolete fungus in the family Boletaceae. The large stout fruit bodies have light to dark grey or gray-brown caps, often with pinkish margins, that may reach 16 cm (6.3 in) in diameter. Initially hemispherical (dome-shaped), they become convex to flat as they mature. The pores are red, the tubes yellow and the flesh is pale yellow, and all become blue when bruised. The stout stipe is bulbous or cylindrical at the base and yellow at the top and pink- to orange-red at its lower parts, and patterned in a fine darker orange or red reticulation. The mushrooms smell of hay when fresh or dried. It closely resembles R. legaliae, though the latter species grows in deciduous forests.

It is found in eastern Europe, east to the Caucasus. It is mycorrhizal, forming associations with spruce (Picea) and fir (Abies), and generally found in montane habitats. The fungus is classified as "critically endangered" in a Redlist of fungi of the Czech Republic.

This is a poisonous mushroom, in its raw form, after boiling is slightly poisonous, the consumption of which can lead to gastrointestinal disorders.

Mushroom Identification

Cap

5 - 16 cm in diameter, fleshy, initially hemispherical, later convex, convex-spread, pillow-spread, spread. The surface of the cap is felt-fibrous, matte, dry, light pink-gray, dark pink-gray, gray-pink-brown, purple.
Hymenophore tubular

Tubules are yellow or pale yellow. The pores are small, red, blood-red, in places of contact acquire a bluish color.
Stem

Thick, cylindrical or club-shaped, thickened at the base, yellowish at the top, pink-red or orange-red in the central and lower part, with red or dark orange mesh.
Habitat and Distribution

Grow in summer, in coniferous, mostly mountain forests, forms mycorrhiza with spruce and fir, which is very rare. Extremely rare species.
Similar Species

Rubroboletus legaliae, grows in deciduous, mostly oak, forests.

History

The bolete was first described from former Czechoslovakia as a subspecies of Boletus splendidus (now Boletus legaliae), and later promoted to species status (as Boletus rubrosanguineus) by Jean-Louis Cheype in 1983. Its species name comes from the Latin words ruber "red" and sanguineus "bloody". It was transferred to the new genus Rubroboletus in 2014 along with several allied reddish, blue-staining bolete species. Molecular analysis of eight of the member species found it was most closely related to Rubroboletus sinicus and formed a larger clade with R. satanas and R. pulchrotinctus