Wikipedia
Umbravirus
The genus Umbravirus includes plant viruses assigned to the family Tombusviridae. The genus has seven recognized species: Carrot mottle mimic virus, Carrot mottle virus, the type species, Groundnut rosette virus, Lettuce speckles mottle virus, Pea enation mosaic virus 2, Tobacco bushy top virus, and Tobacco mottle virus.
Umbraviruses do not encode their own coat protein, but use the coat proteins of 'assistor viruses' from the family Luteoviridae to produce virions, allowing them to be transmitted. Transmission may be by aphids or mechanical inoculation. The genome is a linear, positive-sense, single-stranded RNA, 4200–6900 nucleotides in length.