Mojave indigo-bush, Psorothamnus arborescens, is a species of perennial shrub that brings a brilliant violet and indigo color to the desert and riparian scrublands of Owens Valley. Another species of the shrub, P. emoryi is also known as dyeweed. You may expect the vibrant flowers to be a source of dye, but it was actually the branches that were traditional used to create yellow-brown dye by some Native California tribes. I have not been able to find any sources describing Mojave indigo-bush used in a the same way, but still thought it was fascinating. Photo from me.

Source: Bean LJ, Saubel KS. 1972. Temalpakh (from the earth): Cahuilla Indian knowledge and usage of plants.