Cyano meaning blue and boletus meaning 'lump of clay'
Meaning covered in powder
I commonly encounter this species early in the season and it is this fantastic mushroom, it is in the Bolete family which also includes Porcini (Cep, Penny Bun, Boletus edulis). Like many Boletus it turns blue when handled but this turns from chrome yellow to inky deep blue within seconds when broke in half, very distinctive, everywhere you handled it too it becomes blue, but it fades to a dull grey after around five or so minutes. It grows with oak and beech and my local cemetery produces an abundance of them. There are other Boletes which are yellow that turn blue but none with such impressiveness as this species, you can see on the images how blue it turns when it is damaged.
Late Summer to Autumn.
Habitat & Distribution
Most often found with both Beech (Fagus) and Oak (Quercus), there are a small number of records from coniferous woods. Occasional, There are records acrosss the UK but it does not seem numerous anywhere. There appear to be more records the further south you go.
Research in 2017 suggests that its consumption should be 'restricted' as it can hyperaccumulate arsenic (many mushrooms in general can accumulate heavy metals too, not just this species - which is why you do not pick in polluted areas such as road verges etc).
For more info read here : https://www.sciencedirect.com/science/article/abs/pii/S0308814617314875?via%3Dihub
10.5-14 x 4.5-6.5µm, broadly elliptical to subfusiform.
Spore Print Colour
Scarletine Bolete (Neoboletus luridiformis) also goes a dark blue, but the pores are orange/red and the cap a darker colour and the stem more orange/red too. Bitter Beech Bolete (Caloboletus calopus) has a much redder stem base and the cap is paler, it does not turn as dark blue. Bay Bolete (Imleria badia) is a much browner species with pale pores, not chrome yellow and turns a lighter blue. The poisonous Satan's Bolete or Devil's Bolete (Suillelus satanas) has a much paler, almost white cap and a very red stem and pores and slowly turns blue when damaged then back to the pale flesh colour.