Boletus calopus - Bitter Beech Bolete

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Although Boletus calopus is commonly referred to as the Bitter Beech Bolete, it is often found under oak trees as well as under Beech, and nearly always on chalky soil.

All of the red-pored boletes are fairly rare finds in the UK, but Boletus calopus is one of the more common ones.

The specimens pictured here were seen in a shallow ditch under mature oaks beside a road through The New Forest, in Hampshire.

Identification guide

Cap	5 to 14cm across, often irregularly lobed; vVarious shades of smoky-grey, sometimes with an olivaceous flush; initially slightly downy, becoming smooth at maturity; occasionally cracking or developing small scales in the cap centre; flesh is pale straw yellow quickly turning white when cut and then later turning a striking turquoise-blue.
Tubes and Pores	The yellow tubes terminate in yellow pores that turn blue-green when cut or bruised.

Stem	7 to 9cm tall and 3 to 5cm in diameter; often curved at base; lemon yellow at the apex and flushed red below, becoming a deeper red at maturity; covered in a pale yellow net pattern.
Spore print	Olivaceous snuff-brown.
Odour/taste	Bitter taste; strong and unpleasant fungal smell.
Habitat	Mainly on alkaline or neutral soil beneath Beeces and deciduous oak.
Season	Summer and autumn.
Occurrence	Occasional.
Similar species	Boletus luridus has a darker cap and orange flesh in the stem base; it blues instantly when cut. Boletus satanas has a white cap and orange or red pores when mature; its flesh turns pale blue and then fades to its original pallid colour..