is a yellowish orange citrus

Citrus

Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...

 fruit, a group of cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s of natsumikan

Natsumikan

is a fruit of Japan developed in 1740 with a particularly tart/sour taste.Many Natsumikans are planted in the gardens of residences in Yamaguchi prefecture. The city of Hagi is famous for Natsumikan, particularly Natsumikan juice and ice cream....

(Citrus natsudaidai), which were discovered in 1740 in the Yamaguchi prefecture

Yamaguchi Prefecture

is a prefecture of Japan in the Chūgoku region on Honshū island. The capital is the city of Yamaguchi, in the center of the prefecture. The largest city, however, is Shimonoseki.- History :...

 of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. Natsumikan is about the size of grapefruit

Grapefruit

The grapefruit , is a subtropical citrus tree known for its sour fruit, an 18th-century hybrid first bred in Barbados. When found, it was named the "forbidden fruit"; it has also been misidentified with the pomelo or shaddock , one of the parents of this hybrid, the other being sweet orange The...

 and oblate

Spheroid

A spheroid, or ellipsoid of revolution is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters....

 in shape. The fruit contains 12 segments and about 30 seeds.

Natsumikan is grown commercially in Japan, notably in Kumamoto

Kumamoto Prefecture

is a prefecture of Japan located on Kyushu Island. The capital is the city of Kumamoto.- History :Historically the area was called Higo Province; and the province was renamed Kumamoto during the Meiji Restoration. The creation of prefectures was part of the abolition of the feudal system...

 and Ehime

Ehime Prefecture

is a prefecture in northwestern Shikoku, Japan. The capital is Matsuyama.-History:Until the Meiji Restoration, Ehime prefecture was known as Iyo Province...

 prefecture

Prefectures of Japan

The prefectures of Japan are the country's 47 subnational jurisdictions: one "metropolis" , Tokyo; one "circuit" , Hokkaidō; two urban prefectures , Osaka and Kyoto; and 43 other prefectures . In Japanese, they are commonly referred to as...

. The rough textured fruit is easy to peel and is commonly eaten fresh. It is also used for wide variety of products ranging from marmalade

Marmalade

Marmalade is a fruit preserve made from the juice and peel of citrus fruits, boiled with sugar and water. The benchmark citrus fruit for marmalade production in Britain is the "Seville orange" from Spain, Citrus aurantium var...

s to alcoholic beverages.

The natsumikan tree is believed to be derived from pomelo

Pomelo

The pomelo is a citrus fruit native to Southeast Asia. It is usually pale green to yellow when ripe, with sweet white flesh and very thick albedo . It is the largest citrus fruit, 15–25 cm in diameter, and usually weighing 1–2 kg...

, Citrus grandis or Citrus maxima.