Boletus subtomentosus - Suede Bolete

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Boletus subtomentosus (syn. Xerocomus subtomentosus) is sometimes referred to as the Yellow Cracking Bolete (although the cap does not always crack). An infrequent species, the Suede Bolete is found mainly under broad-leaf trees.

This is a tricky bolete to identify with confidence, but a simple chemical test helps eliminate many options: the cap turns bright mahogany red if you put a spot of KOH (household ammonia is fine) onto it.

Identification guide

Cap	Young caps are hemispherical and downy, becoming smooth and sometimes cracking as the fruiting bodies mature. When fully expanded, the caps of Boletus subtomentosus range from 4 to 8cm in diameter.
Tubes and Pores	The tubes and pores are chrome yellow, darkening with age, and the tubes have adnate attachment to the stem. When cut or bruised neither the tubes nor the pores show any hint of blueing.
Stem	Pale like the cap or slightly darker, the stem is slightly bulbous at the base and its cap-coloured flesh does not change colour significantly when cut and exposed to air. Between 1 to 2cm in diameter, the stem is typically 4 to 8cm long.
Spore print	The spores are olive-green or brown.
Odour/taste	Not distinctive.
Habitat	Found singly or in small groups under broad-leaf trees in calcareous regions.
Season	August to October.
Occurrence	Infrequent.
Similar species	Boletus Chrysenteron has a reddish stem, usually untapered, and its cap cracks to reveal red flesh immediately below the skin.