Ruby Blood Orange × Webber-Fawcett 22 Trifoliate

C-35 Citrange

Estimated Genetic Ancestry

50% Sweet Orange
50% Poncirus trifoliata

Selections

C-35 is a first-generation hybrid of Ruby sweet orange and Webber-Fawcett trifoliate orange from crosses made at the University of California in 1951. UCR describes a relatively small, open tree with trifoliolate leaves, occasional lower-branch dieback in older trees and an average of 8–12 seeds per fruit. Its Riverside accession ripens from November to January.^⁠[1]

C-35 was the seed parent of kumin’s southeastern Pennsylvania trial, begun in 2018 with more than 20,000 seedlings. The breeder described the seed lot as mostly nucellar, with an estimated 15% zygotic component. He explicitly stated that its pollen parent was unconfirmed, so the trial cannot be treated as a controlled self-cross of C-35.^⁠[3]^⁠[4]

During winter 2018–2019, the breeder observed uniform desiccation and severe bark injury among presumed nucellar F1 seedlings, while a small number of other seedlings retained living stems. In March 2020 he clarified that some plants he had considered dead later resprouted from underground roots and might have been C-35. Above-ground survival and root regrowth were different outcomes; seedling identities were not genetically verified.^⁠[5]^⁠[6]^⁠[7]

In the milder winters discussed in January 2021, the breeder reported survival in trees he suspected were C-35, with delayed spring growth and larger protected cold-frame plants. He considered gradual cold acclimation important and warned that severe cold could kill tops or roots. These observations involved uncertain identities and different growing environments, not a tested universal hardiness limit for the cultivar.^⁠[8]^⁠[9]

A vigorous, large-fruited tree in the trial remained unidentified: kumin could not determine whether it was nucellar C-35 or a different seedling. Its 2023 fruit and juice readings are therefore retained as an uncertain seedling report, not C-35 measurements. Seedling variation in January 2024 led him to doubt the parent tree’s true-to-type identity. Likewise, the later video’s C-35-like sample 050 remains unconfirmed. The Conestoga selections are descendants of the C-35 seed lot, not descriptions of C-35 itself.^⁠[10]^⁠[11]^⁠[12]^⁠[2]^⁠[13]