Transition mire communities formed by floating, sometimes drifting, carpets of sphagna, in particular, Sphagnum cuspidatum, Sphagnum recurvum, Sphagnum auriculatum (Sphagnum obesum) or of sphagna and Eriophorum angustifolium. They may constitute fairly large transition mire communities in permanent heath pools, periglacial palsas, large raised bog and blanket bog pools and in former peat extraction holes. They often succeed the communities of unit D2.39 in the colonization process. They have an appearance that ranges from low, barely emerging sphagnum mats to fairly dense cottonsedge beds. Drosera rotundifolia is often abundant. The sphagnum and common cottongrass communities are an important habitat for the threatened bog orchid Hammarbya paludosa.