Acuff, Amarillo, Estacado and Posey soils are on surrounding plains and have an argillic horizon. Arch, Drake, Midessa, Portales, and Pep soils are on slightly higher landscape positions and have 18 to 35 percent clay in the particle-size control section. Very slow permeability. Runoff is negligible. These soils are frequently ponded for long or very long periods in most years.
Vegetation varies according to amount of water available.
It includes knotgrass, bur ragweed, sedges, spike rushes, smartweed, saltmarsh aster, curly dock, frog-fruit, and bushy knotweed. In areas of standing water longbarb arrowhead, soft-stem bulrush, and southern cattail may be present. Around the margins, where ponding occurs for shorter periods the woody vegetation includes western willow and some saltcedar. The series is of moderate extent. Ranco soils were formerly included with the Randall series.