Shaded seepages are found under alder or willow (sallow) woodland in valley bottoms, and under birch or sometimes alder-ash woodland on hillsides. The soil is constantly saturated and usually contains a large proportion of organic matter giving rise to deep ooze.
Vegetation is often limited, although Carex spp may be well developed in some places. Dead wood is an important component of these seepages, as this is the medium for some crane fly larvae.