Cyanoboletus pulverulentus
Cyanoboletus pulverulentus, commonly known as the ink stain bolete, is a species of edible bolete mushroom. All parts of the mushroom will stain dark bluish-black after handling.
It is found in deciduous and mixed forests, particularly on moist soil on slopes and under beech and oak trees. A common species, it is found in northern Asia, Europe, North Africa, Central and northern South America, and eastern North America.
A recent study has revealed this mushroom hyperaccumulates arsenic compounds and therefore consumption should be limited.
Taxonomy
Boletus pulverulentus was first described by German mycologist Wilhelm Opatowski in 1836. The specific epithet pulverulentus means "covered with powder" and refers to the somewhat dry powdery surface of the young cap and stalk. The fungus was transferred to the newly created genus Cyanoboletus in 2014, where it is the type species. Based on the 28S rDNA, North American collection of this fungus reported in the Genbank database does not match that from Europe.Description
The cap is convex, flat when old, dark reddish-brown becoming lighter with age, and grows up to in diameter. The cap cuticle comprises a tissue layer of undifferentiated hyphae measuring 3–7 μm wide.The stalk is long and slender, bright yellow to orange yellow at the top, and reddish-brown at the base. The flesh is yellow, with a mild taste and immediately turns blackish-blue when handled.
The basidia measure 22–35 by 6–9 μm. Spores are smooth, fusoid to elliptical, and measure 11–15 by 4–6 μm. The spore print colour is olive brown.