This is the last in the series on tropical and subtropical fruit. These two photographs are shared by Friedrich K of Heidelburg, Germany, aka fuchsiafred@Flickr (Daniel, April 17, 2011: links to individual original images are dead, so removed) | BPotD Flickr Group Pool). Friedrich had put together a small series on these bergamot oranges (also now removed) to illustrate the making of a traditional liqueur flavoured by the rind of these citrus fruits.
The origins of Bergamot orange are unknown, according to an industry web site, Consorzio del Bergamotto: Reggio Calabria (warning: Flash site). The industry site lists experts having traced its origins to places such as China, Greece, Spain (near Berga) and Turkey — and then fancifully suggests it is of mythical origin as a spontaneous mutation discovered in the city of Fata Morgana, a mirage city purportedly observed in the Strait of Messina (between Sicily and Calabria in Italy). Whatever its origin, somewhere around 90% of the world's production of Bergamot oranges occurs in Calabria.
The economic uses of Bergamot orange are not restricted to flavouring traditional liqueurs, though. Prominent among its modern applications is its use as the major flavouring ingredient for Earl Grey tea. Historically, oils were also extracted from its rind in the production of the original Eau de Cologne (the oil from the petals of Citrus aurantium, the sour (or bitter or Seville) orange are also used). Unfortunately, there have been some consumer difficulties with the oil from the Bergamot orange rind – turns out it can discolour skin and cause burning when exposed to light (i.e., it is phototoxic). The industry is fighting against the trend toward using synthetic Bergamot oil replacements by finding alternative uses for the fruits, such as oils for aromatherapy, juices and marmalade.
A word of caution I should add from Mabberley's “The Plant Book”: he notes that the rind oil is allegedly carcinogenic. The PAN Pesticides Database lists its carcinogenic properties as unknown (it is also used as a dog, cat and insect repellent).