What is this coating?

Today I came across a shrub with this coating on the branches.
Thanks for the feedback on yesterday's family shot.

[Antonio-S]

I'm not an expert on this subject, it seems to be a coating of lichens. Something that is completely natural and even an indicator of good environmental quality, as lichens do not develop in polluted environments.

[Hazel]

@antonios

I think you are right. More developed lichen, called 'bushy lichen' is very beautiful and indicates the purest air

[Brian]

@antonios @quietpurplehaze thank you so much. 🙏

[Hazel]

Brian here's some bushy lichen
https://365project.org/quietpurplehaze/365/2014-02-27