All citrus trees are of the single genus
Citrus, and
remain largely interbreedable; that is, there is only one "superspecies"
which includes
lemons,
limes and oranges. Nevertheless, names have been given to
the various members of the citrus family, oranges often being
referred to as
Citrus sinensis and
Citrus aurantium. Fruits of all members of the genus
Citrus are considered
berries because they have many
seeds,
are fleshy, soft and derive from a single
ovary. An orange seed is sometimes referred to as a
pip.
The Persian orange, grown widely in southern Europe after its
introduction to Italy in the 11th century, was bitter. Sweet
oranges were brought to Europe in the 15th century from
India
by Portuguese traders, quickly displaced the bitter, and are now
the most common variety of orange cultivated. The sweet orange
will grow to different sizes and colours according to local
conditions, most commonly with ten
carpels, or segments, inside.
Portuguese,
Spanish,
Arab,
and
Dutch sailors planted citrus trees along trade routes to
prevent scurvy. On his second voyage in
1493,
Christopher Columbus brought the seeds of oranges, lemons and
citrons to
Haiti
and the Caribbean. They were introduced in Florida (along with
lemons) in
1513
by Spanish explorer
Juan Ponce de Leon, and were introduced to
Hawaii in
1792.
A single
mutation in
1820
in an
orchard of sweet oranges planted at a
monastery in
Brazil led to the
navel orange, also known as the
Washington, Riverside or Bahia navel. A single cutting of the
original was then transplanted to
Riverside,
California in
1870,
creating a new market worldwide. The mutation causes a 'twin'
fruit, with a smaller orange embedded in the outer fruit
opposite the stem. From the outside, the smaller, undeveloped
twin leaves a formation at the bottom of the fruit, looking
similar to the human
navel.
Navel oranges are almost always seedless, and tend to be larger
than other sweet oranges. They are produced without
pollination, through
parthenocarpy. A newer variety of the navel orange, with
pink flesh, is the Cara Cara navel. The
Valencia or
Murcia orange is one of the sweet oranges used for juice
extraction. It is a late-season fruit, and therefore a popular
variety when the navel oranges are out of season. For this
reason, the orange was chosen to be the official
mascot of the
1982 FIFA World Cup, which was held in Spain. The mascot was
called "Naranjito" ("little orange"), and wore the colours of
the Spanish soccer team uniform. The
blood orange has streaks of red in the fruit, and the juice
is often a dark burgundy colour. The fruit has found a niche as
an interesting ingredient variation on traditional Seville
marmalade, with its striking red streaks and distinct flavour.
The
mandarin orange is similar, but smaller and sweeter, and the
scarlet navel is a variety with the same diploid mutation
as the navel orange.