A richly branched "reindeer lichen" which can form large mounds on moorland, heaths and dunes. Very variable, with richly branched, spreading in all directions, typically with holes in the axils of the main branches. Branching mainly trichotomous but can be dichotomous at the tips

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
Ahti, Stenroos & Moberg. editors (2013) Nordic Lichen Flora. Volume 5 Cladoniaceae