esummerbell's Identifications

Although some publications refer to the virus in this observation as Japanese Holly Fern Mosaic Virus or Japanese Holly Fern Mottle Virus, @jameskdouch reports that its correct name is Japanese holly fern mottle pteridovirus. See Rodrigo A. Valverde and Sead Sabanadzovic, "A novel plant virus with unique properties infecting Japanese holly fern," Journal of General Virology (2009), 90, 2542–2549 (https://www.researchgate.net/publication/233739268_A_Strain_of_Japanese_holly_fern_mottle_virus_Infecting_Leatherleaf_Fern_in_the_United_States).
For a brief overview of this virus, written for the general public, see Rodrigo A. Valverde and Sead Sabanadzovic, "New Virus Causing Disease in Japanese Holly Fern," Louisiana Agriculture Magazine, Summer 2008, page 27 (https://www.lsuagcenter.com/portals/communications/publications/agmag/archive/2008/summer/louisiana-agriculture-magazine-summer-2008).

For photos of this virus, see Lisa Hassell, "Insect and Plant Disease Threats to Florida Horticulture" (https://conference.ifas.ufl.edu/gardener17/presentations/1%201030%20Hassell.pdf) and Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University (Blacksburg, Virginia), "The Plant Disease Clinic and Weed Identification Lab Annual Report 2018" (https://spes.vt.edu/affiliated/plant-disease-clinic/reports.html. [Choose 2018 PDF].)