Citrus unshiu is a semi-seedless and easy-peeling citrus species, also known as the satsuma mandarin or Japanese mandarin.

Nomenclature

The Chinese name for the fruit is Wenzhou migan (温州蜜柑), which means "Wenzhou honey citrus". The same name is pronounced Unshū mikan (温州蜜柑) in Japanese, which is the origin of the scientific name unshiu. In Japan, the common name mikan usually refers to this species unless otherwise stated.

An alternative Chinese name, (), means "seedless mandarin".

One of the English names for the fruit, satsuma, is derived from the former Satsuma Province in Japan, from which these fruits were first exported to the West.

The Afrikaans name is also used in South African English. It came originally from the Tamil word , meaning citrus.

Classification

Under the Tanaka classification system, Citrus unshiu is considered a separate species from the mandarin. Under the Swingle system, unshius are considered to be a group of mandarin varieties. Genetic analysis has shown the Satsuma to be a highly inbred mandarin-pomelo hybrid, with 22% of its genome, a larger proportion than seen in most mandarins, coming from pomelo. It arose when a mandarin of the low-pomelo Huanglingmiao or kishumikan variety (placed in C. reticulata by Tanaka) was crossed with a pomelo or pomelo hybrid, then the resulting cultivar was backcrossed with another Huanglingmiao or kishumikan mandarin.

Characteristics

thumb|Satsuma orange trees in Izunokuni, Shizuoka Prefecture, Japan

Citrus unshiu is one of the sweetest citrus varieties. It is usually seedless, and is about the size of other mandarin oranges (Citrus reticulata). Satsumas are known for their loose, leathery skin; the fruit is very easily peeled in comparison to other citrus fruits. The rind is often smooth to slightly rough with the shape of a medium to small flattened sphere. Satsumas usually have 10 to 12 easily separable segments with tough membranes.

History

thumb|Citrus unshiu flower

Origins

Historically, there are two main theories regarding the origin of Citrus unshiu: one proposing a Japanese origin and the other a Chinese origin. The species was named after Unshu (Wenzhou), a famous production area of Citrus species in China, in the late Edo period of Japan.

According to the Japanese origin theory, the species citrus unshiu emerged in Nishi-Nakajima, Higo Province (later Nagashima, Kagoshima), in the 1600s as a result of parent species introduced from China. This theory is supported by the Japanese Ministry of Agriculture, Forestry and Fisheries, Ehime Prefecture, and several Japanese scientists. Before the name unshu mikan was established, it was locally known as nakajima mikan or nagashima mikan after the location of its purported birth.

Genetic studies by Japanese scientists suggest that the maternal parent of Citrus unshiu is kishu (Citrus kinokuni) and the paternal parent is kunenbo (Citrus nobilis Lour. var. kunip).

Spread to the United States

thumb|Satsuma oranges being sold in [[San Francisco, United States]]

Jesuits brought the fruit from Asia to North America in the 18th century, establishing groves at the Jesuit Plantation upriver from New Orleans, Louisiana (then part of New Spain). The municipal street "Orange" in New Orleans was originally named "Rue Des Orangers" after this site. These groves were later relocated further south to Plaquemines Parish, Louisiana, to provide better protection from frost; the Becnel family remains the largest citrus growers in the region today.

The fruit became significantly more common in the United States during the late 19th century. In 1878, Owari mikans were brought from the Satsuma region of Japan to the United States by Anna Van Valkenburgh, the wife of General Robert B. Van Valkenburgh, the US Minister to Japan. She renamed the fruit "satsumas" after their region of origin. Between 1908 and 1911, approximately one million Owari mikan trees were imported and planted across the lower Gulf Coast states. Owari is still commonly grown in Florida. There are, however, some hybrids.

Possible non-hybrids

  • Kishu mikan
  • Ōgonkan or Ki-mikan
  • Komikan

Hybrids

  • Amanatsu (pomelo hybrid)
  • Kinkoji unshiu (C. obovoidea(kinkoji) × C. unshiu)
  • Kiyomi
  • Dekopon is a kiyomi hybrid
  • Kobayashi mikan (C. natsudaidai × C.unshiu)
  • Shonan Gold
  • Iyokan

Uses

Citrius unshiu is widely eaten, and is used in desserts and confections. In China, the peel is also used as medicine.

<gallery mode="packed" widths="160px" heights="160px">

File:5回目のひな誕祭 横浜スタジアム 2024年4月6日の横浜 202404061543 IMG 0559.jpg|Mikan-gori, Japanese shaved ice with orange pieces

File:Putgyul (Citrus unshiu) - making syrup 2.jpg|Korean putgyul syrup, made from unripe oranges

File:Chenpi,陳皮,Citrus unshiu 5026687.JPG|The dried peel is used in Chinese cuisine

</gallery>

References

  • The Satsuma Tangerine – University of Florida
  • PLANTanswers – Texas Cooperative Extension