Citrangequat

The citrangequat (Citrus × georgiana) is a citrus hybrid of a citrange and a kumquat, developed by Walter Swingle at Eustis, Florida, in 1909. Citrangequats are bitter in taste, but are considered edible by some at the peak of their maturity. Three named cultivars exist:
 * 'Sinton' – Nagami kumquat (Fortunella margarita) x Rusk citrange; named for the city of Sinton, Texas
 * 'Telfair' – Nagami kumquat x Willits citrange; named for Telfair County, Georgia
 * 'Thomasville' – most common citrangequat; named for the city of Thomasville, Georgia. 'Thomasville' is considered the most cold-hardy edible citrus variety. It can tolerate temperatures down to −15 °C (5 °F).