Xanthoria ucrainica, one of the species split off from Xanthoria candelaria. It is far less fruticose, that is three dimensiona and has abundant blastidia (similar to soralia) on the lobe margins, and few rhizinae. It is probably the commonest of the smaller Xanthoria species, and is found on richly fertile, often manured habitats. This photograph taken in Jersey on  a poplar. It is often greenish towards the centre of the thallus, though my experience of it is that it is normally much the same colour as other Xanthoria species.