Eriophorum vaginatum
The raised bogs in the Harz are some of the best preserved in central Europe. They were formed at the end of the last ice age about 10,000 years ago. A significant proportion of the vegetation on these raised bogs is made up of peat mosses ("Sphagnum spec."). The flarks ("Schlenken") and the hummocks ("Bulten") are home to different species of flora. In the flarks, for example, "Sphagnum cuspidatum" is found, whereas the hummocks are preferred by "Sphagnum magellanicum". The blanket of peat moss is penetrated by dwarf bushes such as cowberry and blueberry. Bog-rosemary ("Andromeda polifolia") is a relict of the ice age. Other such ice age plants include the dwarf birch ("Betula nana") and few-flowered sedge ("Carex pauciflora"). Cranberries ("Vaccinium oxicoccus") bloom from May to June. The black crowberry ("Empetrum nigrum") may also be seen amongst those bearing black fruit. Common heather (Calluna vulgaris) grows on the drier hummocks and occasionally the cross-leaved heath ("Erica tetralix") may be found. Typical grasses are the sheathed cottongrass ("Eriophorum vaginatum"), known for its bright, white clusters of fruit and deergrass ("Scirpus cespitosus"), which is rust-red in the autumn. One fascinating moorland plant is the round-leaved sundew ("Drosera rotundifolia"). Bog or northern bilberry (Vaccinium uliginosum) grows on the drier margins of the bog.