Ol modified horizon, temporarily influenced by stagnic water or groundwater. Vegetation indicates wetness in the topsoil.
[w from water-influenced]

  1. organic carbon content ≥ 15 mass % and
  2. developed under aeromorphic to aero-hydromorphic conditions
  3. temporarily reducing conditions and
  4. distinct grey to black colouration and
  5. above recently water-influenced hydromorphic A or H-horizon

(-> Moist L-Mull)

Owl-horizon, humus form: Moist F Mull, strong influenced by stagnic water, © Gerhard Milbert