1. Clay-rich soils that shrink and expandl with changes in moisture content.

During dry periods, the soil shrinks, and significant vertical cracking and deep wide cracks form; but, as it gets water, the soil expands.

Typically forming under grassland vegetation in basins or rolling hill landscapes, Vetisols are best suited for use as pastureland and for the cultivation of plants; such as, rice, which thrives in standing surface water.

Vertisols are divided into six suborders: Aquerts, Cryerts, Xererts, Torrerts, Usterts, and Uderts all of which are defined in this unit.

2. From the U.S. Soil Taxonomy soil-order classification system.
3. Etymology: from Latin vertere, "to turn".