[wikipedia] Habitat, Edible Roots, Psammorphory: The plant grows in succulent mats on sand or other coastal substrate. The roots are stout, fusiform and often several feet long. These roots are edible, traditionally eaten by the Chinook Indians.[3] This plant is seen exhibiting psammophory, a method by which plants save themselves from herbivores by attracting sand to their body making them difficult to be eaten.[4] It needs salt water, not fresh water, and will not tolerate extreme drought.[5] (link added by Mary Ann Machi)