The fruit of the lemon tree (Citrus limon) in the citrus genus (Citrus), about the size of a fist, is known as the lemon (from Italian citrone) or limone. It is a series of varietals that evolved in northern India from a hybrid between bitter orange (Citrus aurantium) and citron (Citrus medica). The first credible records can be discovered in China and the Mediterranean region about the year 1000.

Lemons are elongated oval fruits with yellow or green-yellow skin that are produced by evergreen trees. The juicy, acidic flesh is high in vitamin C and includes roughly 3.5-8 percent citric acid. Lemons are used to extract juice, citric acid, essential oil, and pectin.

Etymology and history

Before the middle of the 16th century, the word “lemon” was derived from Italian citrone, which was influenced by French citron. Because the word for the fruit (in the 16th century also citron apple) dates back to Greek kedrómlon (“cedar apple,” name of the citron lemon) in reference to the aroma, the Latin name citrus (in the 16th century German Citronenbaum) is regarded a distortion from cedrus (“cedar”). The citron was once known as the lemon. In several languages, it wasn’t until the late Middle Ages that the word was changed to lemon. However, in other languages, such as English, the term citron still refers to the citronate lemon, whilst the word lemon, taken from Arabic, refers to the lemon. For centuries, the word limone was also a widespread name for the lemon in German, and it still is in some parts of Austria. The word limonade was derived from the French language and originally referred to a delicious lemon drink. In some contexts, the word lemon is used to refer to the sour citrus fruits lime, citron, and lime as a group.


The lemon is an evergreen tree that develops to be small to medium in size. They are huge and fast-growing when compared to other citrus plants. Small, thin thorns cover the young shoots in especially. The branches are reddish, the buds are pink, and the undersides of the white petals are pink to purple.

The leaves are elongated-oval to broadly lanceolate, pointy, and have a somewhat serrated or notched edge. The leaf stem is a little wider (winged), and the leaf blade is clearly separated from the stalk (unifoliate leaf).

The occasionally foul-smelling flowers occur in sparsely flowered inflorescences throughout the year. They are 20 to 30 mm in diameter and contain five fused sepals and five free petals. The ovary is thickly cylindrical and joins the pistil at the base. The filaments and the 20 to 40 stamens are joined together to create multiple clusters.

Insects are the most common pollinators in Citrus, but wind pollination and self-fertilization by direct contact of the stamens with the stigma are also prevalent. Because Citrus is partly pollen-sterile or the stigma is not fertile, parthenocarpy, or fruit without fertilization, results in seedless fruits. Blossoms with atrophied gynoeciums, or flowers that are functionally male, are common.

Untreated lemons

The fruit (hesperidium) has eight to ten segments, each of which is packed with pale yellow sap tubes. A thin membrane (endocarp) surrounds each segment, and a two-part peel surrounds the entire fruit. The peel’s inner layer is white (mesocarp, albedo), the outer layer green when mature (exocarp, flavedo), and yellow in subtropical locations in winter. In Europe, lemons are generally handled such that the peel is always yellow when they arrive on the market. The peel has many oil glands and emits a fragrant scent. The leaves have a lemon scent to them as well. At the fruit’s tip, there is normally a tiny protuberance. The seeds are tiny and pointy, with a smooth surface. They’re white on the inside. Polyembryonic seeds account for 10 to 15% of all seeds.


Lemons are mostly used as a food, but they can also be used as a decorative plant. Lemon juice has been used as a contraceptive in the past.

The grated peel of the lemon, in addition to the juice, is frequently used as a flavoring element in cooking and baking (see lemon yellow). Only the peel of an untreated lemon is edible; citrus fruits are typically coated in a waxy protective coating and sprayed with preservatives like 2-phenylphenol (E231) or thiabendazole (E233) before being transported. Biphenyl (E230) was also utilized in the past. It is deemed unhealthy to consume such peels. Lemon oil is made from untreated lemon peels.

The kaffir lime leaves, sometimes known as “lemon leaves,” are mostly utilized in Thai cuisine.


Lemons are high in phosphorus and pectin, as are all citrus fruits, and also contain water, fat, potassium, calcium, magnesium, and vitamin C.

Medicinal plant

The medicines that were used were:

Lemon oil is the essential oil extracted from fresh lemon peels. Lemon peel, i.e. the pericarp’s dried or fresh outer covering.

Active ingredients

Essential oil with limonene (65-70%) and citral, which gives the scent its distinctive character.

hydroxycoumarins, furanocoumarins, citric acid, and pectins; bitter flavonoids neohesperidin and naringenin; non-bitter rutin; hydroxycoumarins, furanocoumarins, citric acid, and pectins.


Lemon peel is frequently included in tea blends and fruit teas. The essential oil is mostly used as a flavor and odor enhancer, but it is also utilized in rubs as a minor skin irritant. Preparations for venous disorders and flu-like illnesses contain isolated citrus flavonoids.

Ornamental plant

Lemon trees grow well in Central Europe, and they used to be an important part of orangeries. The lemon tree is unique in that it produces both blooms and fruit throughout the year. The lemon should be placed outside in a shaded position from mid-May until the first frost. The temperature must be adjusted to the light conditions in the winter. The leaves will still have enough light for photosynthesis if the lemon trees are placed in bright but chilly settings, but the roots will nearly totally cease activity at 12.5 °C. The tree will be unable to produce blossoms or fruit as a result of this.As a result, the tree can no longer provide sufficient nutrients to the leaves, which causes them to drop. As a result, the “winter leaf drop” occurs. Scale insects are a prevalent nuisance in the United States.