Boletus calopus    Pers.:Fr. 

common name(s) : Bitter Beech Bolete, Beech Bolete, Scarlet-stemmed Bolete 

New classification: Basidiomycota/Agaricomycotina/Agaricomycetes/Agaricomycetidae/Boletales/Boletaceae  
Former classification: Basidiomycota/Homobasidiomycetes/Agaricomycetideae/Boletales/Boletaceae/Boletoideae [ section:Calopodes ]  

synonyms: Caloboletus calopus, Boletus pachypus, Tubiporus calopus 

edibility : discard

photo gallery of  Boletus calopus
photo gallery of  Boletus calopus potential confusions with  Boletus calopus toxicity of Boletus calopus genus Boletus  

The cap is white, pale grey, buff to pale brown, fleshy, thick, of convex then more or less flattened shape. The cap margin is thick, inrolled a long time, then expanded.

The stem is thick, full, of variable shape: bulbous-swollen, spindle-shaped or more or less equal. It is sulphur-yellow towards its apex, then dark red in most of its surface, and brown towards the base, turning blue when touched. The white mycelium shows at the stem base. It is covered with a sharp and regular network, with polygonal cells, white towards the top and with the same colour as the background elsewhere. It fades away with age from the bottom up, but keeps being visible at the stem top..

The flesh is thick, firm, whitish to pale lemon yellow, with brown or purple at the base. It turns moderately blue when in contact with air, before fading to pale blue-grey; its taste is first mild, then bitter; the odour is varying: from weak or acidic, to strong and unpleasant;

The tubes are thin, easily removed from cap, rather long (10-15mm), lemon yellow then greenish, round, turning blue when exposed to air.

The pores are small, round, dull yellow then greenish yellow (concolorous to tubes), turning blue-green when pressed. The spore print is olive brown.

It grows in coniferous forests, but it can also be found with broad-leaved trees. It comes isolated or in small troops, more often in the mountains than in low grounds. This species is present in the west and centre of France, on a rather acid soil, with spruce, beech, chestnut.

The fruiting period takes place from June to November.
Dimensions: width of cap approximately 11 cm (between 3 and 20 cm)
  height of stem approximately 9 cm (between 4 and 15 cm)
  thickness of stem (at largest section) approximately 35 mm (between 10 and 60 mm)
  spores : 10-18 x 3,5-5,5 microns, spindle-shaped

Chemical tests : strong reaction to iodine : dark green then dark blue.

Distinctive features : Whitish to buff brown cap; red stem, with a raised whitish network; yellow pores, turning blue when pressed; pale yellow flesh, with bitter taste, turning blue when exposed to air

Boletus calopus is quite rare and localised in the forest of Rambouillet, and is occasional, more generally speaking .
here should be the distribution map of Boletus calopus in the forest of Rambouillet
Above : distribution map of Boletus calopus in the forest of Rambouillet



page updated on 14/01/18