Fruiting body: a mould that grows on members of the Boletales. Developes in three stages, at first white and enveloping the whole fungus as in the illustration above, then becoming bright yellow, then in the last stage becoming reddish brown and developing pustules on the surface.

Flesh: powdery but adhering tightly to the Bolete surface.

Spores: stage one spores are asexual; ellipsoid;10 – 30 × 5 – 12 µm; stage 2 spores globose; 10 – 25 × 10 – 25 µm; thick walled, warty.

Notes: Hypomyceschrysospermusis recognised by the white or bright yellow mould on Boletes and can be confirmed by examining the spores. This mould is common on most Boletes.