Soil families are distinguished within a subgroup primarily on the basis of properties importantto the growth of plants or on the behavior of soils when used for engineering. Among the properties considered are texture, mineralogy, reaction, soil temperature, permeability, thickness of horizons, and consistence. A family name consists of a series of adjectives preceding the subgroup name. The adjectives are the class names for texture, mineralogy, and so on, that are used asfamily differentiae. An example is the fine-silty, mixed, mesic family of Typic Fragiaqualfs.

10/15/98