Chinese orange may refer to:
- Citrus medica, fragrant citrus fruit
- Poncirus trifoliata, member of the family Rutaceae, closely related to Citrus
- Mandarin orange, small citrus tree with fruit resembling other oranges
The citron (Citrus medica) is a large fragrant citrus fruit with a thick rind. It is one of the original citrus fruits from which all other citrus types developed through natural hybrid speciation or artificial hybridization. Though citron cultivars take on a wide variety of physical forms, they are all closely related genetically. It is used in Asian cuisine, traditional medicines, perfume, and religious rituals and offerings. Hybrids of citrons with other citrus are commercially more prominent, notably lemons and many limes.
The trifoliate orange, Citrus trifoliata or Poncirus trifoliata, is a member of the family Rutaceae. Whether the trifoliate oranges should be considered to belong to their own genus, Poncirus, or be included in the genus Citrus is debated. The species is unusual among citrus for having deciduous, compound leaves and pubescent (downy) fruit.
The plant is a fairly cold-hardy citrus (USDA zone 6) and will tolerate moderate frost and snow, making a large shrub or small tree 4–8 m (13–26 ft) tall. Because of its relative hardiness, citrus grafted onto Citrus trifoliata are usually hardier than when grown on their own roots.
The mandarin orange (Citrus reticulata), also known as the mandarin or mandarine, is a small citrus tree fruit. Treated as a distinct species of orange, it is usually eaten plain or in fruit salads. Tangerines are a group of orange-coloured citrus fruit consisting of hybrids of mandarin orange with some pomelo contribution.
Mandarins are smaller and oblate, unlike the spherical common oranges (which are a mandarin–pomelo hybrid). The taste is considered sweeter and stronger than the common orange. A ripe mandarin is firm to slightly soft, heavy for its size, and pebbly-skinned. The peel is thin, loose, with little white mesocarp, so they are usually easier to peel and to split into segments. Hybrids usually have these traits to a lesser degree. The mandarin is tender and is damaged easily by cold. It can be grown in tropical and subtropical areas.
According to genetic studies, the mandarin was one of the original citrus species; through breeding or natural hybridization, it is the ancestor of many hybrid citrus cultivars. With the citron and pomelo, it is the ancestor of the most commercially important hybrids (such as sweet and sour oranges, grapefruit, and many lemons and limes). The mandarin has also been hybridized with other citrus species, such as the desert lime and the kumquat. Though the ancestral mandarin was bitter, most commercial mandarin strains derive from hybridization with pomelo, which give them a sweet fruit.