A scarce but widespread Cladonia which seems often to be misidentified in online photos, and not well illustrated in most lichen guides.  The tattered, rather half-dead-looking podetia (the antler- or cup-like structures of a Cladonia) are distinctive  - described in keys as 'longitudinally lacerate' but often looking as if they divide and join up again, and appear to have bits dropping off them, hence the English name. Usually richly fertile, and found on sandy soils, both on heaths and in lichen turf in gravel pits, and potentially on sand dunes too.