Adiantum jordanii is a perennial species of maidenhair fern, in the Vittarioideae subfamily of the Pteridaceae. The species is known by the common name California maidenhair. It is native to California and Baja California. A. jordanii is found in the southernmost part of its range in Baja California with such flora associates as Mimulus aridus and Daucus pusillus. Each trailing leaf may reach over half a meter in length and is made up of many rounded green segments. Each segment has two to four lobes and it may split between the lobes, the underside of each segment bearing one to four sori.