History

Seed Germinated

US-1515 originated from open-pollinated seed of Nagami kumquat planted at the A.H. Whitmore Foundation Farm in Florida in 1975. The pollen parent is unknown. Later observations suggested that US-1515 may itself be a kumquat hybrid, possibly involving mandarin ancestry, but this has not been established well enough to record a specific pollen parent.

Sources: ⁠[1]

Other

In 1986 H. C. Barrett observed a spontaneous variegated mutation on a small twig of US-1515. That mutated branch was subsequently propagated and became the cultivar Centennial Variegated kumquat.

• H. C. BarrettOther

  Observed the spontaneous variegated twig mutation on US-1515 in 1986 that became Centennial.

Sources: ⁠[1]