The orange contains a number of distinct carpels (segments) inside, typically about ten, each delimited by a membrane, and containing many juice-filled vesicles and usually a few seeds ( pips). Inside and attached to the rind is a porous white tissue, the white, bitter mesocarp or albedo ( pith). Sweet oranges grow in a range of different sizes, and shapes varying from spherical to oblong. Its oval leaves, alternately arranged, are 4 to 10 cm (1.6 to 3.9 in) long and have crenulate margins. The orange tree is an evergreen, flowering tree, with an average height of 9 to 10 m (30 to 33 ft), although some very old specimens can reach 15 m (49 ft). Orange applies primarily to the sweet orange- Citrus sinensis ( L.) Osbeck. ĭifferent names have been given to the many varieties of the species. The fruit of any citrus tree is considered a hesperidium, a kind of modified berry it is covered by a rind originated by a rugged thickening of the ovary wall. As the interfertility of oranges and other citrus has produced numerous hybrids and cultivars, and bud mutations have also been selected, citrus taxonomy is fairly controversial, confusing or inconsistent. This includes grapefruits, lemons, limes, oranges, and various other types and hybrids. Taxonomy and terminologyĪll citrus trees are angiosperms, belong to the single genus Citrus, and remain almost entirely interfertile. In 2019, 79 million tonnes of oranges were grown worldwide, with Brazil producing 22% of the total, followed by China and India. As of 2012, sweet oranges accounted for approximately 70% of citrus production. The fruit of the orange tree can be eaten fresh, or processed for its juice or fragrant peel. Orange trees are widely grown in tropical and subtropical climates for their sweet fruit. As of 1987, orange trees were found to be the most cultivated fruit tree in the world. The orange originated in a region encompassing Southern China, Northeast India, and Myanmar, and the earliest mention of the sweet orange was in Chinese literature in 314 BC. The sweet orange has had its full genome sequenced. The chloroplast genome, and therefore the maternal line, is that of pomelo. The orange is a hybrid between pomelo ( Citrus maxima) and mandarin ( Citrus reticulata). The sweet orange reproduces asexually ( apomixis through nucellar embryony) varieties of sweet orange arise through mutations.

An orange is a fruit of various citrus species in the family Rutaceae (see list of plants known as orange) it primarily refers to Citrus × sinensis, which is also called sweet orange, to distinguish it from the related Citrus × aurantium, referred to as bitter orange.

Oranges are not