Citrofortunella

Citrus hybrids include many varieties and species that have been selected by plant breeders, usually for the useful characteristics of the fruit. Some citrus hybrids occurred naturally, and others have been deliberately created, either by cross pollination and selection among the progeny, or (rarely, and only recently) as somatic hybrids. The aim of plant breeding of hybrids is to use two or more different citrus varieties or species, in order to get intermediate traits, or the most desirable traits of the parents. In some cases, particularly with the natural hybrids, hybrid speciation has occurred, so the new plants are considered a different species from any of their parents. Citrus hybrid names are usually marked with a multiplication sign after the word "Citrus", for example Citrus × aurantifolia.

Citrus taxonomy is very complex and this page currently follows the Swingle system.

The most known citrus hybrids that are sometimes treated as a species by themselves, especially in folk taxonomy, are:

Graft-chimaeras, also called graft hybrids, can occur in Citrus. The cells are not somatically fused but rather mix the tissues from scion and after grafting, a popular example the Bizzaria orange. In formal usage, these are marked with a plus sign "+" instead with an "x".

Citrofortunella according to the Swingle system, is a hybrid genus, containing intergeneric hybrids between members of the genus Citrus and the closely related Fortunella. It is named after its two parent genera. Such hybrids often combine the cold hardiness of the Fortunella, such as the Kumquat, with some edibility properties of the citrus species. Citrofortunellas, which are all hybrids, are marked with the multiplication sign before the word "Citrofortunella", for example × Citrofortunella microcarpa or × Citrofortunella mitis which refer to the same plant.

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