Allenrolfea occidentalis, the iodine bush, is a low-lying shrub of the Southwestern United States, California, Idaho, and northern Mexico.

[3] It grows in sandy, often salty, distinctly alkaline soils, such as desert washes and saline dry lakebeds.

It is a common halophyte member of the alkali flat ecosystem.

[3] The knobby green stems are fleshy and appear jointed at the internodes between segments.

The genus was named for the English botanist Robert Allen Rolfe.