Western Gall Rust

The type collection of this species was made in May 1876 by H. W. Harkness and Justin P. Moore, found growing on a young ponderosa pine tree in the vicinity of Colfax, California. The finding was presented at a meeting of the San Francisco Microscopical Society in July 1876 in a talk by Harkness before the group, describing the natural history, taxonomic relationships, and pathogenic potential of this newly-discovered species of Peridermium. Justin P. Moore motioned that the fungus be named Peridermium Harknessii in honor of Dr. Harkness, and the vote of the society was unanimously in favor. Peridermium Harknessii was formally published in 1884 in an article by Harkness on new species of California fungi, but with authorship of the species name specifically attributed to Justin P. Moore so as to avoid the informal but strong prohibition in taxonomy for naming an organism's scientific name after oneself. By the 1920s, it was known that other similar species of Peridermium were simply the aecial phase of Cronartium and that in keeping with the convention of dual nomenclature for many species of fungi that take different morphological forms through a complex life cycle, E. P. …