Tufts of flattened, black branches arising from single holdfast. Apothcia, often shiny with spiny edge to the disc. Upland areas on siliceous rocks

References: 
Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Dobson, F.S. (2018) Lichens: an Illustrated Guide to the British and Irish Species
Thell & Moberg, editors (2011) Nordic Lichen Flora, Volume 4: Parmeliaceae