Very common on dead stems and roots of poroporo. This is the cause of 'silver scurf' disease of potatoes.

The current wikipedia entry says ''This pathogen is a fungus which is specific to infecting only potato tubers", which apart from the questionable English, is factually incorrect. The fungus was first described from Solanum nigrum, not S. tuberosum, and is known from other Solanum species, and indeed other plant genera.