Orange (fruit)
An orange—specifically, the sweet orange—is the 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...

 Citrus ×
Hybrid name
In botanical nomenclature, a hybrid may be given a hybrid name, which is a special kind of botanical name. The ICBN provides the following options in dealing with a hybrid:...

(Citrus Sinensis (L.) Osbeck) and its fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

. It is the most commonly grown tree fruit in the world.

The orange is a hybrid of ancient cultivated origin, possibly between 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 maxima) and mandarin
Mandarin orange
The orange, also known as the ' or mandarine , is a small citrus tree with fruit resembling other oranges. Mandarin oranges are usually eaten plain or in fruit salads...

 (Citrus reticulata). It is an evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 tree generally growing to 9–10 m in height (although very old speciments have reached 15 m).