High Quality Content by WIKIPEDIA articles! A Gleysol (Russian: gley is dialectical word глей, literally "clay") in the FAO World Reference Base for Soil Resources is a wetland soil that, unless drained, is saturated with groundwater for long enough periods to develop a characteristic gleyic colour pattern. This pattern is essentially made up of reddish, brownish or yellowish colours at surfaces of soil particles (peds) and/or in the upper soil horizons mixed with greyish/blueish colours inside the peds and/or deeper in the soil. Gleysols are also known as Gleyzems and meadow soils (Russia), Aqu-suborders of Entisols, Inceptisols and Mollisols (USDA soil taxonomy), or as groundwater soils and hydro-morphic soils.