Like the pattern of the commons, their vegetation is also concentrically arranged. At the heart of each of Dartmoor's two plateaux is a substantial area of blanket bog underlain by up to two metres of peat and characterised by cotton grass, deer grass, rushes and bog mosses (mainly sphagnum). Surrounding them in a figure-of-eight are peaty soils, often waterlogged, bearing heath, with ling dominant, and grass moorland where purple moor grass gives it a raffia-like colour in winter. Outside that is a narrower and more variable zone of patches of vegetation, some occupying whole commons, dominated by gorse or bracken or short-cropped grass often with some heathers - all suggesting better and drier soils.
Gorse, Ling and Purple Moor Grass