Arum fungus

Hello Mark

I’ve seen similar things and they never turned out to be fungal. In any case Phoma and Phyllosticta species do not affect their substrates in this way – for example there is no evidence of any dead plant material associated with the dots in your images.

Without seeing much more detail of the dots I can’t say more. It’s always worth seeing whether such dots are superficial and can be removed with, say, a damp tissue.

Regards

Chris