Rhizomorpha subcorticalis
Rhizomorpha subcorticalis is a species name that has been used to characterize certain fungal plant pathogen observations where the pathogen is evident only through mycelial cords ("rhizomorphs"). The species in question very likely also produces reproductive structures which would allow it to be situated in the normal taxonomic tree, especially if DNA analysis is available. A name like "R. subcorticalis" should only be used where such identification is impossible. History. The species name was first validly published by Persoon in 1801 with acknowledgement of an earlier description by P. Micheli, describing the fungus as consisting of brownish-black  branches and being found between bark and heartwood (which is the meaning of ""subcorticalis""). "Rhizomorpha" "fragilis" is listed as a synonym, indicating that the "real" species may have been "Armillaria mellea" ("Honey Fungus"). Another given synonym is "Clavaria phosphorea" which was described in 1797 by James Sowerby - the epithet "phosphorea" indicates that it glows in the dark, which is also true of "Armillaria" rhizomorphs. Someone has annotated with the word "Rhizomorpha". The name has been used for a crown and root rot disease of strawberry and avocado, where according to the American Phytopathological Society the fungus in question is indeed  actually "Armillaria mellea". In 1871 in his book on diseases of forest trees, Robert Hartig mentioned "R. subcorticalis" as well as "R. fragilis" contrasting them as different species, the former being thinner and softer and having little tissue in the interior of the strands. So here "R. subcorticalis" must represent something other than "Armillaria mellea".