Lichen ID please

[Tringa]

Spotted this on piece of twig in our back garden in East London.

I don't know what tree it is growing on, it is not one in our garden. I think it has blown in or been dropped by a bird. The nearest trees are sycamore, lime, oak and plane.

The largest of the cups is about 3mm across.



Anyone know what it is?

TIA

Dave

[JennyS]

Hi Dave,

Its Xanthoria parietina. Abundant and increasing in lots of area's as it thrives on nitrogen enrichment

[Tringa]

Thanks Jenny.