Also known as organic soils, Histosols are developed by the accumulation of organic material in an anaerobic environment. Histosols are black to dark brown in color and are more commonly known as peats or mucks.

Histosols are also most commonly found in wetlands. Its organic makeup is mostly water plants such as cattails, sedges, reeds, mosses, shrubs, and some trees.

Histosols can form in any climate but are more prevalent in cold climates like that of Alaska, Canada, Finland and Russia and in formerly glaciated regions such as Michigan, New York, and Wisconsin. They are also found in low-lying tropical and subtropical areas such as the everglades in Florida and the bayous of Louisiana.

Suborders:
  1. Fibrists. Fibers of the parent material (plants) can be identified. Also known as peats.
  2. Folists. Folists form from leaf mat accumulations.
  3. Hemists. Fibers are partially decomposed so not all of the parent material can be identified. Also known as mucky peats.
  4. Saprists. Also known as mucks, the fibers in this soil are fully decomposed and not identifiable.