observation indicated it was on a tree trunk, I’d be inclined to guess that the host is a Fistulinella. Proximity to, or on, wood is often where I have seen this genus – but not always. Other mycophiles in Australia have said the same thing to me.
Go here to see Boletellus emodensis fruitng inside a dead log on Fraser Island.
Once in a while, I’ve seen Syzigites (a bread mold related to Mucor) on Strobilomyces.

on other fungi from very different genera …and it is not often easy to come to a decision in trying to determine them. But as far as I know you are right in Hypomyces concerning Boletes but when it comes to species it isn’t that easy anymore … there has been a lot of research recently and many (new?) species have been introduced.

“a Tylopilus or a Fistulinella but strongly spread with mould”

Does anyone know what genera (other than Hypomyces) of fungi parasitize the fruiting bodies of other fungi, appearing as a mould growth (as opposed to a jelly-like, parasitic fungi, for example)?

Hypomyces is just a guess, based on the macroscopic resemblance of this to H. chrysospermus I’ve seen on local Boletus spp. .

Thanks Gerhard, I did think along those lines, but as you have read I was unable to actually get close due to the topography. Chow kk

either a Tylopilus or a Fistulinella but strongly spread with mould and therefore impossible to come to a conclusion with…I found similar ones in Leura Forest…
it’s the problem with too much rain!