Also known as Hawaiian cotton, Gossypium tomentosum was once extremely common to the dry and rocky coastal areas of the Hawaiian islands. It now is threatened by coastal development and the spread of alien invasive weeds. This plant is rare by all standards including ICUN, the World Conservation Union, and is also protected under the Endangered Species Act. Although closely related to commercial cotton, the fibers of Gossypium tomentosum have not been used to produce cotton on a large scale. Hawaiian cotton has been important in research and breeding programs aimed at producing disease resistance in commercial cotton. It was crossed with other cotton strains to create a hybrid that is pest resistant. Historically, native Hawaiians used the bright yellow flowers to make dye.