Oroblanco

Oroblanco was developed as a cross between a diploid acidless pomelo and a seedy white tetraploid grapefruit, resulting in a triploid seedless fruit that is less acidic and less bitter than the grapefruit.[2]

The oroblanco was patented by the University of California in 1981 after its development by Robert Soost and James W. Cameron[3][4][5][6][7] at that university's citrus experiment station in Riverside, California.[8] The nine-year project began in 1958 and led to a series of test plantings before a successful variation was refined.[2]

Juvenile tree of "Oroblanco" in Missouri Botanical Gardens.

Sweetie

Oroblancos are either round- or oval-shaped with a thicker rind than grapefruit. When eaten, an oroblanco lacks bitterness associated with grapefruits and is rather sweet, even when the outer peel is still green, but the white membranes separating the fleshy segments are bitter and usually discarded.[9]

Oroblancos are available from September through December. They may be peeled and eaten like an orange — by separating into segments — and are often eaten at breakfast.[10]

A similar fruit has been commonly cultivated in Israel since 1984, from where the name "Sweetie" originated.[11][12] It is also referred to as a "pomelit."

• 
  An Oroblanco
• 
  An extreme flattened specimen of Oroblanco

• Southern California has three fine locally adapted hybrids at their peak now: Oroblanco, Melogold and Cocktail. David Karp in Los Angeles Times
• UC, Davis
• Oregon Live