Common resupinate found on many tree species, both decidous and coniferous, with a southern bias. The fungus is quite smooth and of a whitish-cream colour, usually found on the underside of twigs and branches, but also on stumps

References: 
Hugill & Lucas (2019) The Resupinates of Hampshire
Bernicchia & Gorjón (2010) Fungi Europaei, 12: Corticiaceae s.l.
Læssøe & Petersen (2019) Fungi of Temperate Europe, Volume 2