Sources

Cunningham citrange (opens in a new tab)

Givaudan Citrus Variety Collection at UCR

https://citrusvariety.ucr.edu/crc0271 (opens in a new tab)

Accessed September 18th

Exocortis Disease of Citrus: top-root relationships of trifoliate orange and its hybrids studied in search for cause of root disease (opens in a new tab)

W. P. Bitters · California Agriculture · 1952

https://californiaagriculture.org/article/114506-exocortis-disease-of-citrus-top-root-relationships-of-trifoliate-orange-and-its-hybrids-studied-in-search-for-cause-of-root-disease.pdf (opens in a new tab)

Vol. 6, no. 11 (1952), pp. 5–6. Historical Riverside progress report on exocortis in citrus rootstock/scion combinations. Results depend on scion strain and trial setup; the reported observations do not establish cultivar-wide immunity.

Accessed October 2nd

Nucellar seedlings: may permit development of disease-free citrus varieties (opens in a new tab)

James W. Cameron; J. C. Johnston · California Agriculture · 1949-01

https://californiaagriculture.org/article/114956-nucellar-seedlings-may-permit-development-of-disease-free-citrus-varieties.pdf (opens in a new tab)

January 1949, printed pp. 9–12. Riverside progress report on old-line and nucellar-line citrus trials; Cunningham is named among four rootstocks, but no isolated Cunningham-specific vigor or disease result is reported.

Accessed October 2nd

Citroncirus Citrange Cunningham Clon Livurce (Frey) Z97 (opens in a new tab)

Eisenhut Vivaio Baumschule

https://www.eisenhut.ch/en/product/18460 (opens in a new tab)

Nursery listing item Z97 explicitly names the clone Cunningham Clon Livurce (Frey); the page description applies to that listed clone. Identity equivalence with UCR CRC 271 is unconfirmed. The page's description is in Italian.

Accessed October 2nd

New Citrous Fruits (opens in a new tab)

Walter T. Swingle · American Breeders Association · 1913

https://archive.org/details/journalofheredit04ameruoft (opens in a new tab)

Swingle's paper, read January 25, 1913, reports the 1897 crossing series and identifies Cunningham among the named citranges. It supports a documented-by-1913 boundary and Swingle's program involvement, not an individual naming act or a Cunningham-specific cross date.

Accessed October 9th

Citrus Breeding in Florida—Past, Present and Future (opens in a new tab)

W. C. Cooper, P. C. Reece, and J. R. Furr · Proceedings of the Florida State Horticultural Society · 1962

https://journals.flvc.org/fshs/article/view/100828 (opens in a new tab)

Printed p. 7 reports reciprocal Poncirus trifoliata × Ruby sweet-orange crosses in 1897, citing Swingle (1913), and says 11 named citranges were grown from a single fruit. Official PDF retrieval was blocked; the passage was checked in a full-text transcription against the official article record.

Accessed October 9th