Xerotrema quercicola

Xerotrema quercicola is a species of lichen in the family Odontotremataceae. The species was described in 2008 from material collected on a standing, barkless oak trunk in Scotland, and is characterised by its small, dark brown apothecia with distinctively green-tinged margins. It is endemic to Great Britain, where it inhabits the hard wood of dead oak trees in veteran woodland settings.