Geography and distribution
Black pepper is native to the Western Ghats of Kerala State in India, where it grows wild in the mountains.
It is cultivated all over the tropics as a commercial crop. Vietnam, Indonesia, Brazil and India are the major producers.
Overview: A climber that grows to a height or length of 10 m or more. Once the main stem is established it grows many side shoots to create a bushy column.
Piper nigrum (black pepper)
The plants form short roots, called adventitious roots, which connect to surrounding supports.
Leaves: Almond-shaped, tapering towards the tip, dark green and shiny above, paler green below, arranged alternately on the stems.
Flowers: Borne in clusters along flowering stalks known as spikes. 50–150 whitish to yellow-green flowers are produced on a spike.
Fruits: Round, berry-like, up to 6 mm in diameter, green at first but turning red as they ripen, each containing a single seed. 50–60 fruits are borne on each spike.
Fruits are picked when green and immature to produce green pepper; when fully grown but still green and shiny to produce black pepper; and when slightly riper to produce white pepper (for which the fruits are also soaked to remove the fleshy outer layer).
Other pepper plants
Other plant species are also known as pepper or peppercorns and are used in a similar way as black pepper, for example, Indian long pepper, Piper longum, which has a milder flavour than black pepper. It is native from Assam to Burma, and is a cultivated crop in the drier regions of India.
Pink pepper is obtained from Schinus terebinthifolia (Brazilian pepper tree). It grows as a tree, is in a different plant family, Anacardiaceae (cashew family), from black and long pepper and is native to South and Central America. Its pinkish-red fruits often enter European markets where it is used as a black pepper-like flavouring.
Sichuan pepper, a common spice used in Asian cuisine, is obtained from Zanthoxylum species (citrus family, Rutaceae).
Peppercorns should not be confused with chilli peppers (Capsicum species) such as Capsicum annuum (potato family, Solanaceae).
The fruits of Piper nigrum are used to make black pepper. This hotly pungent spice is one of the earliest known and most widely used spices in the world today. It is used as flavouring, particularly for savoury foods, meat dishes, sauces and snack foods. It is also used as a table condiment.
Piper nigrum (black pepper) mixed peppercorns
Black pepper, white pepper and green peppercorns are all produced from Piper nigrum fruits, but are harvested at different times and are processed differently.
India is a key producer of black pepper and exports much of what is grown. Peppercorns from Malabar and Tellicherry in Kerala, India, are particularly prized for their flavour and pungency.
Black pepper is also used to produce pepper oil and oleoresin, which are frequently used in the production of convenience foods and sometimes also for perfumery.
Of lesser importance is the use of preserved immature green pepper or fresh pepper fruits, which are eaten more like a vegetable.
Black peppercorns feature as remedies in Ayurveda, Siddha and Unani medicine in South Asia. They are most frequently used as an appetizer and to treat problems associated with the digestive system, particularly to eradicate parasitic worms. Some traditional uses of black pepper are supported by scientific evidence.
In Ayurvedic medicine, black pepper has been used to aid digestion, improve appetite, treat coughs, colds, breathing and heart problems, colic, diabetes, anaemia and piles. Stomach ailments such as dyspepsia, flatulence, constipation and diarrhoea are all treated with black pepper, which may be mixed with other substances such as castor oil, cow's urine or ghee.
Black pepper has been prepared in tablet form as a remedy for cholera and syphilis, sometimes combined with other substances. It has also been used in tooth powder for toothache, and an infusion of black pepper has been suggested as a remedy for sore throat and hoarseness. Black pepper may be chewed to reduce throat inflammation.
Externally, it has been applied as a paste to boils and to treat hair loss and some skin diseases. Oil of pepper is reputed to alleviate itching. A mixture of sesame oil and powdered black pepper has been recommended for application to areas affected by paralysis. A mixture of black pepper and honey is regarded as a remedy for night blindness. Black pepper has been given by inhalation to comatose patients. It is also believed to be useful against hepatitis, urinary and reproductive disorders. In Ayurveda and Siddha medicine, a paste made using white pepper is applied to treat some eye diseases.
In Unani medicine, black pepper has been described as an aphrodisiac and as a remedy to alleviate colic. A preparation called 'jawa rishai thurush' is composed of pepper, ginger, salt, lemon juice and the plants vidanga (Embelia ribes; Primulaceae, primrose family) and mint (Mentha species; Lamiaceae). It has been prescribed to alleviate indigestion and stomach acidity.
Black peppercorns contain compounds called alkaloids. One of these is piperine, reported to act as a central nervous system depressant and to have anti-fever, pain-relieving, anti-inflammatory and insecticidal effects. Some experiments suggest black pepper and its constituent piperine may have potential in the treatment of vitiligo (loss of skin pigment) as it helps increase pigmentation in the skin.
Black pepper is also reported to have anti-fungal and anti-oxidant properties.
Millennium Seed Bank: Seed storage
The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Watercolour of Piper nigrum by Janet Hutton
A collection of Piper nigrum seeds is held in Kew’s Millennium Seed Bank based at Wakehurst in West Sussex.
Black pepper is a tropical vine with attractive almond-shaped leaves, which needs to be grown indoors in temperate regions. With patience it can be grown as a houseplant to produce peppercorns (although plants need to be several years old before they fruit).
Propagation is usually by seed. Plants are not unduly affected by pests or diseases (even aphids dislike the taste of the leaves).
This species at Kew
Black pepper can be seen growing in the Palm House and Princess of Wales Conservatory at Kew.
Dried and spirit-preserved specimens of Piper nigrum are held in Kew’s Herbarium where they are available to researchers by appointment. The details of some of these specimens can be seen online in Kew’s Herbarium Catalogue.
Specimens of the seeds, roots and fruits of black pepper, as well as pepper oil obtained from it, are held in Kew’s Economic Botany Collection, where they are available to researchers by appointment.