The citrus fruit trees belong to the Rutaceae plant family; citrus trees are prevalent in the tropical and Mediterranean areas of the world, although with the introduction of the orangery and greenhouses, it has become popular to grow citrus trees indoors in countries with colder climates, such as the UK.
Citrus trees are now also common in the predominantly sunny states of the USA, such as California and Florida. With the introduction of many hybrids and cultivars of the citrus fruit, many citrus fruits look similar in appearance; there are many different species of the orange, for example, which is also often confused with the tangerine.
The Orange Trees
The orange trees are perhaps the most versatile of the citrus trees, producing two different species of oranges, in addition to a number of essential oils which can be used in aromatherapy. It is important to note that there are three different varieties of orange trees, the sweet orange (Citrus sinensis), the bitter orange (Citrus aurantium) and the bergamot orange (Citrus bergamia), in addition to many cultivars and hybrids
Identification of the Orange Trees
The bitter orange tree is a tall tree (of 33 feet in height) with dark green, glossy leaves, sharp spines and fragrant white flowers and small orange fruit; the sweet orange tree is smaller in size but has larger fruit. The sweet orange tree is unable to survive in colder climates, unlike the bitter orange tree. The bergamot tree grows to about 15 feet in height and has small, round fruit which looks like a miniature orange but actually ripens from green to yellow in color.
The Lime Tree
The lime (Citrus aurantifolia) citrus fruit is used interchangeably with the lemon citrus fruit, as both fruits have similar medicinal properties and culinary uses, and are closely related. The lime tree grows up to 15 feet in height, has smooth, oval leaves and small white flowers. The fruit of the lime tree is approximately half the size of the lemon and is pale green in color.
The Lemon Tree
The lemon (Citrus limon) citrus tree grows up to 20 feet in height, has oval leaves with aromatic flowers; the fruit of the lemon tree ripens from green to yellow in color. In addition to being a close relative of the lime tree, the lemon is also closely related to the bergamot tree. There are many varieties of lemons which have been cultivated.
The Tangerine Tree
The tangerine (Citrus reticulata) is also known as the mandarin or satsuma, although, botanically, there are some differences between the tangerine and mandarin, most notably in the size of the fruit in various cultivars; in general, the tangerine tree grows up to 20 feet in height, has aromatic flowers and glossy leaves and is well known throughout the USA. In Europe, the tangerine is more commonly referred to as the mandarin.
The Grapefruit Tree
The grapefruit (Citrus paradisi) is a recent cultivar, believed to be a hybrid of the pummelo fruit (Citrus maxima) and the sweet orange (Citrus sinesis). The grapefruit tree is 33 feet in height, has glossy, green leaves and the fruit is large and yellow; in the USA, it is a common sight in California.
Identifying the Citrus Trees
Citrus trees are botanically close relatives and are used for similar uses both medicinally and in the kitchen, sharing a number of similar properties and characteristics; however, it is useful to know the differences in the size and colors of the various citrus trees to be able to identify the many cultivars and hybrid citrus fruits now available.
References:
Lawless, Julia 1995 The Illustrated Encyclopedia of Essential Oils UK:Thorsons
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