1. Soils that are formed in volcanic ash or other volcanic material which is discharged.

Andisols are divided into eight suborders: Aquands, Gelands, Cryands, Torrands, Xerands, Vitrands, Ustands, and Udands all of which are defined in this unit.

2. From the U.S. Soil Taxonomy soil-order classification system.
3. Etymology: from Japanese an do, "dark soil".