Adiantum shastense, a new species of maidenhair fern from California

Abstract

A new species of Adiantum is described from California. This species is endemic to northern California and is currently known only from Shasta County. We describe its discovery after first being collected over a century ago and distinguish it from A. jordanii and A. capillus-veneris. It is evergreen and is sometimes, but not always, associated with limestone. The range of Adiantum shastense Huiet & A.R.Sm., sp. nov., is similar to several other Shasta County endemics that occur in the mesic forests of the Eastern Klamath Range, close to Shasta Lake, on limestone and metasedimentary substrates.