Inkstain Bolete

Cyanoboletus pulverulentus

Cap: cm across  Stem: cm in length, cm diameter

Cyano meaning blue and boletus meaning  'lump of clay'

meaning covered in powder

Overall: a medium sized Bolete which is usually solitary or in small groups. The rate of how quickly this species turn deep blue when bruised is a key identification feature.

‚ÄčStem: lemon-yellow always at the apex becoming redder down the stem, sometimes brownish. Turns blue on holding and the flesh of the stem turns very dark blue.

Flesh: yellow, but turns deep inky blue with in a few seconds, this remains one of its key characteristics.

Pores: tightly packed together, lemon yellow becoming darker with age. Quickly turning dark blue on touching or damaging.

Cap:  begins velvety and  convex becoming smooth as it matures. Where it cracks with age or has been eaten by slugs, squirrels etc, it becomes rather reddish. Often dry and where it is handled turns blue.

OVERALL: 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) and is good to eat. 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, they fill a nice void before the flush of Porcini appear. One of the few poisonous species in the Bolete family is pinker and paler than this and turns a light blue when damaged and is much rarer, confined to chalk woodlands. If in doubt though leave it out.  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.


HABITAT: Most often found with both Beech (Fagus) and Oak (Quercus), there are a small number of records from coniferous woods.


DISTRIBUTION: 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.


SEASON: Late summer to autumn.


EARLIEST DATE:  19th July (2008)                LATEST DATE: 27th October (2007)


EDIBILITY: 2/5, whilst this mushroom is edible and I and a few others think it is good, it could be considered too uncommon to warrant picking (my local patch seems to be a stronghold for it), indeed you would probably struggle to find any quantity of these to be able to get enough. The colour it goes in the pan is also not desirable.


EASE OF IDENTIFICATION: Possibly the easiest Bolete to identify, the speed in which it turns from yellow to deep blue is very charecteristic.


SMELL: Nothing distinctive.


OLD ENGLISH NAMES: Blackening Bolete


SYNONYMS: Boletus pulverulentus Opat. Xerocomus pulverulentus (Opat.) E.-J. Gilbert. Boletus radicans sensu Rea (1922) & sensu auct. mult.  


SIMILAR SPECIES: Scarletina 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.

Tel. 07533 132 129 


Manchester, Cheshire, Deeside & North Wales

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