About Adiantum jordanii Müll.Hal.
Adiantum jordanii is a perennial maidenhair fern species belonging to the Vittarioideae subfamily of the Pteridaceae family. Its common name is California maidenhair. This species is native to California and Baja California; in the southernmost portion of its Baja California range, it grows alongside plant associates Mimulus aridus and Daucus pusillus. Its trailing leaves can grow over half a meter long, and each leaf is composed of many rounded green segments. Each segment has between two and four lobes, and may split between these lobes. One to four sori grow on the underside of each segment. Adiantum jordanii acts as a carrier of Phytophthora ramorum, the fungus-like oomycete that causes Sudden Oak Death. The United States Department of Agriculture enforces import controls that focus heavily on U.S. areas infected with Sudden Oak Death: California, Oregon, and New York. When this fern is sold, it must be labeled with its place of origin and accompanied by a phytosanitary certificate. The USDA also warns against taking cuttings from wild Adiantum jordanii specimens. Plants of this species sourced from native plant nurseries are used in native plant gardens and wildlife gardens.
