They are known generally as big tarweeds. The genus contains four species of tarweeds, which are all endemic to California. The "Hemizonia" tarweeds are native to southwestern North America, especially California. Deinandra is a genus of tarweeds in the daisy family. These tarweeds have sticky seeds that facilitate distribution by migrant birds. The closest modern relatives of the silverswords today are California tarweeds of the family Asteraceae. "Harmonia" is related to "Madia", and both genera are commonly known as tarweeds.