Hypomyces aurantius

The asexual stage produces hyaline conidia; originally these were given the name 'Cladobotryum' before the connection with the sexual state was understood.  The sexual stage is more often recorded; it is parasitic on old polypores, and produces a dense pimply crust of orange perithecia in a loose cobwebby white subiculum over the surface of the polypore.  The perithecia are pear-shaped and stain purple with Potassium Hydroxide (KOH).  Ascospores are released from the perithecia; these are two-celled, long and with sharp pointed ends.  

host/microscopy

Microscopic examination and treatment with KOH is needed.  Note habitat and substrate.

Grows densely clustered on the fungal fruit bodies of rotting polypores (bracket fungi).