Cross Made
Cooper, Reece, and Furr (1962), citing Swingle (1913), report reciprocal Poncirus trifoliata × Ruby sweet-orange crosses at Eustis in 1897 and say 11 named citranges were grown from a single fruit. Cunningham is one of the named citranges in their account. This is a historical report, not an independent verification of the pedigree of the individual accession.
Sources: [6]