- Protologue: Sp. pl.: 28 (1753); Gen. pl., ed. 5: 18 (1754).
- Family: Piperaceae
- Chromosome number: x = 12, 13, 14, 16; 2n = 24 (P. cubeba); 2n = 24, 44, 48, 52, 96 (P. longum); most New World species are diploids; Old World species polyploids
Major species and synonyms
- Piper cubeba L.f., Suppl. pl.: 90 (1782), synonym: Cubeba officinalis Raf. (1838).
- Piper longum L., Sp. pl.: 29 (1753), synonyms: P. latifolium Hunter (1809), Chavica roxburghii Miq. (1844).
- Piper nigrum L. - see separate article.
- Piper retrofractum Vahl, Enum. 1: 314 (1804), synonyms: P. chaba Hunter (1809), Chavica retrofracta (Vahl) Miq. (1844), Piper officinarum (Miq.) C. DC. (1869).
- Pepper (En)
- Poivre (Fr)
- Indonesia: lada, uceng-ucengan
- cubeb, tailed pepper (En)
- Poivre cubèbe, poivre à queue (Fr)
- Indonesia: kemukus (Javanese), rinu (Sundanese), pamukusu (Sulawesi)
- Malaysia: kemukus, lada berekur, chabai ekur
- Vietnam: tiêu thất
- Indian long pepper (En)
- Poivre long (Fr)
- Malaysia: chabai
- Cambodia: môrech ansai
- Laos: 'i:x lô:z
- Thailand: phrik-hang (central)
- Vietnam: tiêu lôt, tat phắt, tắt bạt
- Javanese long pepper (En)
- Poivre long de Java (Fr)
- Indonesia: cabe jawa (general), lada panjang (Sumatra), cabia (Sulawesi)
- Malaysia: chabai jawa, bakek, kedawak
- Philippines: litlit (Tagalog), amaras (Iloko), boyo-boyo (Tagbanua)
- Laos: sali: pi:
- Thailand: dipli (general), dipli-chuak (peninsular)
- Vietnam: tiêu dội
Origin and geographic distribution
Piper comprises about 1200 species, distributed pantropically but with most of them occurring in the neotropics. Over 400 species have been recorded for the Malesian region. Most pepper spices originated from South and South-East Asia. P. cubeba is a native of Indonesia (Java, Sumatra, Kalimantan) and is also cultivated in Java, less commonly in Singapore and Peninsular Malaysia and rarely elsewhere. P. longum grows wild at the foot of the Himalayas in north-eastern India. It is widely cultivated in India and Sri Lanka but only occasionally elsewhere, including South-East Asia. P. retrofractum occurs wild from Thailand, Indo-China, Malaysia and the Philippines to the Moluccas, and occurs semi-wild in the Ryukyu Islands. It is also cultivated in northern Peninsular Malaysia and Java.
Pepper, in particular the dried fruit of P. nigrum, is one of the oldest spices and is certainly the most important spice in the world. It has extensive culinary uses and is medicinally renowned for its stimulating action on the digestive organs. The other peppers dealt with here are of much less importance worldwide than P. nigrum. Locally in South and South-East Asia, however, their role is important, sometimes more as medicinal plants than as a spice.
The dried, unripe stalked fruits of P. cubeba were used as a spice in Europe from the Middle Ages onwards, but later their medicinal use became dominant. Cubebs are applied as stimulants to the genito-urinary mucous membrane. They are also applied to the bronchial mucous membrane, for example to treat bronchitis and coughs. They are an ingredient in many mixtures given as tonics against indigestion, are a popular aphrodisiac in Java, and are used as a diuretic, antiseptic and as a medicine against gonorrhoea, amoebic dysentery and rheumatism. In the United States the regulatory status "generally recognized as safe” has been accorded to cubebs (GRAS 2338) and cubeb oil (GRAS 2339). The oil is used as a flavour component in major food products, including alcoholic and non-alcoholic beverages. The maximum permitted level for cubeb oil in food products is about 0.004%. The maximum level for use as a fragrance component in soaps, detergents, creams and alcoholic perfumery is 0.8%.
P. longum is probably the first known pepper in the Mediterranean region; in Rome at the time of Pliny it was twice as expensive as black pepper and more highly esteemed. The whole spikes, which consist of minute fruits embedded in a fleshy rachis, are used as a spice. In Indo-China and many areas of India the medicinal application of fruits and sliced, dried rootstock and stem parts is more important than the use as a spice. P. longum is said to be effective against coughs, asthma, dyspepsia and paralyses, and it has laxative and carminative properties. It is believed that the older the product the better it works. In China the powdered root is given to pregnant women to speed up delivery.
P. retrofractum resembles P. longum and is used similarly. The spice is the dried, unripe infructescence, which is an ingredient of pickles, preserves and curries. It is applied medicinally as a tonic and against a variety of digestive and intestinal disorders. A tincture is used in childbirth to bring about the expulsion of the placenta. It is applied against haemorrhoids, irritation of the skin and many other complaints. In Indonesia a leaf extract is used as a mouthwash and to alleviate toothache. In the Philippines the root is chewed or a decoction is used as a cure for colic. In Malesia the roots of wild peppers are used to prepare poisons.
Production and international trade
Compared with P. nigrum, the production and trade of other Piper spp. are negligible. Local production and trade are important, but there are no recent statistics. At the end of the 19th and in the early 20th Century P. cubeba fruits were exported from Indonesia to Europe and the United States and sometimes fetched high prices. Exports were about 270 t in 1925 and were 135 t on average per annum until 1940. Later in the 20th Century only local trade and some trade via Singapore to India remained. P. cubeba is predominantly a smallholder's crop. P. longum is only of importance in India, with modest export to other Asian countries. P. retrofractum is exported from Indonesia to Peninsular Malaysia, Singapore, China and in small amounts to Europe and the United States, but outside the Far East it is practically a forgotten spice. In the 1920s annual export from Java amounted to 200-250 t.
P. cubeba spice has an aromatic odour but the taste is somewhat bitter and acrid. Cubebs contain cubecic acid (1%), the colourless, crystalline cubebin and about 10-20% essential oil (cubeb oil). Cubeb oil can be obtained by steam distillation of the unripe, dried, crushed fruits. The oil is pale greenish-yellow to bluish-yellow or sometimes colourless, somewhat viscous with a very dry-woody but warm-camphoraceous, spicy-peppery odour. The oil consists mainly of sesquiterpenes (cadinene, dipentene), sesquiterpene alcohols and minor amounts of monoterpenes and is useful in soap perfumes and in woody-peppery perfume bases. Cubeb oleoresin is used for flavouring. It can be obtained by extracting crushed fruits with a hydrocarbon solvent or with ethyl alcohol. The oleoresin has a warm-spicy, peppery odour and taste, but is not very pungent. It is used in spice blends, e.g. for pickles and meat sauces, and to flavour tobacco. Its main constituent is cubeb oil. A monograph on the physiological properties of cubeb oil has been published by the Research Institute for Fragrance Materials (RIFM).
P. longum infructescences contain 4-6% piperine and 0.9-1.5% cadinene. The essential oil distilled from the spikes has an odour reminiscent of ginger, is used as a food flavouring with a milder taste than pepper oil but is hardly traded outside India.
P. retrofractum spice has an agreeable aromatic taste but is more pungent than black pepper and Indian long pepper. It contains piperine, resin, fibrous material 10-15%, starch 44-49%, ash 8%, fixed oil and essential oil. The yield of essential oil after distillation is about 1%; it has an odour of ginger, is viscid and light green but is not traded.
Piper cubeba: Cubeb oil (Source: Lawrence, 1980.)
- 11.0% β-cubebene
- 10.4% copaene (unknown isomer)
- 10.0% cubebol
- 8.8% δ-cadinene
- 7.1% α-cubebene
- 4.9% α-humulene
- 4.6% sabinene
- 4.2% allo-aromadendrene
- 3.7% β-caryophyllene
- 3.7% calamenene
- 3.7% cesarone
- 3.5% nerolidol (unknown isomer)
- 3.5% epi-cubebol
- 2.2% α-terpineol
- 2.0% α-pinene
- 1.5% β-bisabolene
- 1.2% α-muurolene
- 1.2% β-elemene
- 1.0% 10-α-cadinol
- 0.7% 1,8-cineole
- 0.3% apiole
- 0.2% α-thujene
- 89.4% total
Piper longum: Indian long pepper oil !Source: Shankaracharya et al., 1997.)
- 17.8% pentadecane
- 17.0% β-caryophyllene
- 11.2% β-bisabolene
- 6.8% tridecane
- 5.7% heptadecane
- 5.0% α-zingiberene
- 4.9% germacrene D
- 3.7% cis-β-farnesene
- 3.0% spathulenol
- 2.6% globulol
- 2.3% heptadecene
- 1.9% α-humulene
- 1.8% pentadecene
- 1.8% germacrene B
- 1.5% α-copaene
- 0.9% tridecene
- 0.8% γ-elemene
- 0.8% α-gurjunene
- 0.6% γ-terpinene
- 0.5% undecanone
- 0.5% isopulegyl acetate
- 0.5% acetophenone
- 0.5% β-elemene
- 0.4% limonene
- 0.4% 1,8-cineole
- 0.4% β-bourbonene
- 0.3% δ-cadinol
- 0.2% nonadecane
- 0.1% undecane
- 0.1% terpinen-4-ol
- 0.1% para-cymene
- 0.1% nonadecene
- 0.1% linalool
- 0.1% cuminaldehyde
- 0.1% cubenol
- 0.1% δ-elemene
- 0.1% α-ylangene
- 0.1% α-terpineol
- 0.1% α-phellandrene
- 0.1% α-cubebene
- trace α-pinene
- trace β-pinene
- trace β-selinene
- trace γ-muurolene
- trace calamenene
- trace camphor
- trace myrcene
- trace naphthalene
- 95.0% total
Adulterations and substitutes
Genuine cubebs can be distinguished from other pepper fruits by their stalked fruits which are very distinctive and by the seed inside the fruit which is only basally attached to the fruit wall. Cubeb can be distinguished from other products by sprinkling cubeb powder onto 80% sulphuric acid: a characteristic crimson colour appears, owing to the presence of about 1% cubecic acid. In the past, when cubebs fetched high prices, they were adulterated with fruits of other pepper species: P. baccatum Blume, P. caninum Blume, P. crassipes Korth., P. guineense Schum. & Thonn., P. mollissimum Blume, P. nigrum, and even with fruits of the non-pepper species: Bridelia tomentosa Blume (Euphorbiaceae), Lindera spp. (Lauraceae), Litsea cubeba (Lour.) Pers. (Lauraceae), Pericampylus glaucus (Lamk) Merrill (Menispermaceae), Rhamnus spp. (Rhamnaceae), Xylopia frutescens Gaertner (Annonaceae) and Zanthoxylum rhetsa (Roxb.) DC. (Rutaceae).
- Herbs, shrubs or slender trees, occasionally scandent, usually terrestrial. Stems thickened at the nodes, often hollow. A single prophyll is usually present at the shoot apex.
- Leaves alternate, entire, symmetrical or asymmetrical, sometimes deeply lobed at the base, usually palmately 3- or more-veined, petiolate. Indumentum present or absent, hairs simple or multicellular, minute pellucid glands often present.
- Inflorescence spicate, solitary, leaf-opposed, pedunculate.
- Flowers without sepals and petals, subtended by triangular to semilunar bracts, often crowded on a fleshy rachis; stamens 2-6, anthers 2-thecous, filaments short to exserted; ovary unilocular with single basal ovule, style present or absent.
- Fruit a berry or drupaceous, often fleshy, globose, ellipsoidal to obovoid.
- Perennial, woody, dioecious climber, 5-15 m long. Twigs glabrous.
- Leaves firmly coriaceous, subglabrous, lower surface with numerous small sunken glands; petiole 0.5-2 cm long; blade ovate to oblong, 8-15 cm × 2-9 cm, base cordate to rounded, apex tapering to acuminate.
- Spike 3-10 cm long, female ones shortest and often curved, peduncle up to 2 cm long; male flower with oblong-obovate bract of up to 2 mm × 1 mm and 3(-5) stamens; female flower with oblong bract up to 5 mm × 8 mm, stigmas 3-5.
- Berry on 3-15 mm long stipe, globose, 6-8 mm in diameter, red-yellow, drying to black.
- Seed globose.
- Perennial, dioecious herb with woody rootstock and slender prostrate or ascending shoots.
- Leaves thinly membranous, not glossy, gland-dotted; petiole up to 1.2 cm long, longest in lower leaves, upper leaves almost sessile and amplexicaul; blade ovate, 4-7 cm × 2-3 cm, cordate at base, acute or acuminate at apex.
- Fertile branches erect, 30-60 cm tall, bearing erect inflorescences; peduncle 1-2 cm long; bracts peltate, orbicular; male spike 3-6 cm × 1.5-2 mm, flowers crowded, each with 2 stamens; female spike 1.4-3 cm × 3-8 mm, flowers crowded, each with 3-4 stigmas.
- Berries concrescent, forming a thin, fleshy, slender, cylindrical infructescence.
- Perennial, soft woody, dioecious herb, creeping or climbing with adhesive roots, up to 10 m long.
- Leaves glabrous, firmly coriaceous, with many sunken gland dots beneath; petiole 0.5-3 cm long; blade ovate to oblong, 8-20 cm × 3-13 cm, base cordate, obtuse or cuneate, apex tapering or acuminate.
- Spikes erect or patent; peduncle 1-2 cm long; bracts broadly ovate, 1-2 mm long; male spike 2.5-8.5 cm long, stamens 2(-3), very short; female spike 2-3 cm long, stigmas 2-3, short, persistent.
- Infructescence cylindrical, about 2-4 cm × 4-8 mm on a stalk 1 cm long; berries connate and adnate to stalk of bract, broadly rounded, hard and pungent when green, becoming soft and sweet and finally bright red-brown when fully mature, often covered with a grey dust.
- Seed globose, 2-2.5 mm in diameter, white and mealy inside.
Growth and development
Rooted cuttings of P. cubeba can reach a length of about 80 cm in the first year. P. cubeba starts flowering and fruiting the first year after planting, but full productivity is reached after about 3 years when planted below 300 m altitude and after about 4 years when planted at higher altitudes. Plants can remain productive for 50-60 years. In India P. longum flowers and fruits in and toward the end of the rainy season. In Indo-China infructescences mature in January. Its economic lifetime is about 3-5 years, after which the crop is rejuvenated. P. retrofractum is a vigorous climber, but if not pruned regularly when cultivated, it rarely flowers. When plants are kept at a height of about 5 m, flowering and fruiting are year-round.
Other botanical information
The taxonomy of Piper is highly confusing and needs to be revised. A revision would possibly combine species with fused or partly fused ovaries and fruits into a separate genus (e.g. in Chavica Miq.).
Several cultivars of P. cubeba are distinguished in Indonesia, but their identity is obscure and their nomenclature not regulated. The cultivars with the vernacular names "rinu katuncur” and "rinu cengke” are considered as true cubeb cultivars; "rinu badak”, "rinu carulang”, "rinu pedes” and "rinu tembaga” are said to be false cubebs.
The infructescences of P. longum and P. retrofractum are markedly distinct from P. nigrum. In the latter the infructescence bears a number of distinct berries and the spice is the dried berry. In the former two the numerous tiny fruits fuse to form a cylindrical spike-like cone which, when dried, constitutes the long pepper spice.
In the literature P. sarmentosum Roxb. ex Hunter is sometimes considered as identical with P. longum. However, P. sarmentosum is a distinct species, widely distributed in South-East Asia and rarely used as a minor spice, while P. longum hardly occurs in Malesia.
Numerous Piper species are occasionally used as a spice, or more often medicinally. Those not dealt with in this volume or referred to other volumes of the Prosea handbook are mentioned below:
- P. baccatum Blume. A vigorous climbing pepper of Java, Borneo and the Philippines. (Indonesia: bodeh (Javanese), rinu, rinu manuk (Sundanese); Philippines: sambanganai). The vines can reach 30 m length; leaves circular-ovate, 8-18 cm × 3-12 cm; spikes drooping, unisexual, thin; fruit a stalked, globose berry. The juice of the plant is drunk as a cough remedy and the shredded leaves are used as a poultice for the neck. Fruits are very spicy and are used in tonics and have been used to adulterate cubebs.
- P. decumanum L. Occurring in the Philippines, Sulawesi, Moluccas and New Guinea. (Philippines: baragit (Bagobo), buyog (Manobo), malapagba (Bukidnon)). It is a glabrous, dioecious climber; leaf blade ovate, 40 cm × 18 cm, length/breadth ratio 2/1; male inflorescences as long as leaves, female ones longer, stigma 2-lipped to 3-fid; infructescence up to 60 cm long; fruit cylindrical, 3 mm × 1.5 mm. The fruits are used medicinally.
- P. febrifugum C. DC. Occurring in Peninsular Malaysia ("akar sangkap”). It is a large-leaved hairy climber with long spikes. A decoction of the leaves is used against fever.
- P. fragile Benth. Occurring in the Philippines, Moluccas, New Guinea and Solomon Islands. (Philippines: litlit-anito (Tagalog)). It is a dioecious climber, glabrous; leaf blade ovate, 8 cm × 6 cm, length/breadth ratio 4/3; inflorescence shorter than leaves, female ones very short; male flowers 2 stamens, female flowers with 4-fid stigma; fruit globose, 3 mm in diameter. The fruits are used medicinally.
- P. guineense Schum. & Thonn. (synonym: P. clusii DC.). Guinea pepper, black West African pepper, Ashanti pepper. It grows in tropical West and Central Africa and the fruits are used as a condiment and as a substitute for cubebs (African cubeb).
- P. longifolium Ruiz & Pavón. A species from tropical America used medicinally.
- P. medium Jacq. A species from tropical America where it is used to make a drink.
- P. pinnatum Lour. Occurring in Indo-China. Parts of the plant are put in washing water to impart a pleasant smell to clothes.
- P. ribesioides Wallich. Occurring from Burma (Myanmar) to Peninsular Malaysia (lada rimba, akar kalong ular, dunlok) and Sumatra. Crushed leaves are used for poulticing in cases of swellings. The fruit is also used as an adulterant of cubebs.
- P. saigonense C. DC. A wild and cultivated pepper of Vietnam (Saigon pepper (En), poivre de Saigon (Fr), lolo (Vietnamese). Its fruits are used as a spice, just like black pepper. It is possibly identical to P. nigrum.
- P. stylosum Miq. Occurring in Malaysia (kadok hutan), Sumatra and Borneo. The leaves are used as a vegetable. The roots are used medicinally.
- P. subbullatum K. Schum. & Lauterb. (synonym: P. torricellense Lauterb.). Occurring in the Philippines, New Guinea, Bismarck Archipelago, Solomon Islands, Vanuatu. A dioecious shrub to soft wooded tree; leaf blade asymmetrically broad ovate, up to 28 cm × 21 cm; inflorescence up to 40 cm long, female ones shortest; male flowers 2-staminate; female flowers sessile with 3-fid stigmas; fruit obconical. The fruits are used medicinally. P. subbullatum is possibly the ancestor of P. methysticum Forster f., the well-known kava plant of the South Pacific.
The following species are not related to Piper but contain the term pepper in their vernacular names:
- African pepper (Guinea pepper, negro pepper): fruit of Xylopia aethiopica A. Rich. (Annonaceae);
-Capsicum peppers (cayenne pepper, chili pepper, red pepper, green pepper, sweet pepper): fruits of Capsicum spp. (Solanaceae);
- Jamaica pepper (allspice, pimento): fruits of Pimenta dioica (L.) Merrill (Myrtaceae);
- Melegueta pepper: seeds of Aframomum melegueta (Roscoe) K. Schum. (Zingiberaceae);
-Pepper tree (American pepper): fruits of Schinus molle L. (Anacardiaceae);
- Wild Chinese pepper: fruit of Zanthoxylum armatum DC. (syn. Z. alatum Roxb.) (Rutaceae).
Piper species mostly grow in moist habitats, frequently in cleared or disturbed forest areas. They are often opportunist colonizers, growing along roadsides, forest tracks or streams, wherever more light penetrates. In Java, P. cubeba occurs abundantly at the edges of mangrove forest and is grown from sea-level up to 700 m altitude, preferably shaded. P. longum prefers drier conditions and most areas in South-East Asia are not suitable for its cultivation. P. retrofractum preferably grows in deciduous forest on poor soils, up to 600 m altitude, but also along beaches.
Propagation and planting
In Indonesia, particularly in Central Java, P. cubeba is propagated by cuttings, preferably taken from basal shoots. Potted cuttings are kept under shade and are planted out against a support tree as soon as they have rooted. Popular support trees are shade trees in coffee and cocoa plantations, like silk tree (Albizia chinensis (Osbeck) Merrill) and kapok (Ceiba pentandra (L.) Gaertner). Propagation by seed is also possible but usually less successful. In general the cultivation of P. cubeba is like P. nigrum, but the plants are weaker and more difficult to grow. P. longum is propagated by stem cuttings or shoots planted in a rich, well-drained soil. When the rainy season starts the cuttings are transplanted to the field, at 1.5 m spacing, often in mixed cropping systems. In Java, cultivated P. retrofractum is propagated by cuttings.
After planting, P. cubeba is regularly weeded. The young basal shoots are removed and the plants are trained up support trees. Once they reach 1.5 m height (after about 1 year) they receive no further care. Ultimately 1 male plant is retained to pollinate about 9 female plants in the vicinity. In India, P. longum does not require much attention as soon as the crop is established. After harvest, the aboveground parts usually wither and the rootstock is protected against the sun in the dry season by mulching. In Java, P. retrofractum is mainly collected from the wild. When planted, it is given artificial support or is trained up support trees such as Erythrina spp., Dolichandrone spathacea (L.f.) K. Schumann, Borassus flabellifer L., or Moringa oleifera Lamk; it is pruned regularly to promote flowering and fruiting. In East Java, P. retrofractum is also alley-cropped. Support trees are planted along both sides of field plots, with a spacing of 8-15 m between rows and 1.5-2 m in the row. TSP fertilizer is applied one month after planting the pepper cuttings. Earthing up is done twice and weeding is done 4-5 times a year. The support trees are first pruned when P. retrofractum has climbed into them; they are pruned again if their foliage becomes too dense.
Diseases and pests
The major diseases and pests of P. nigrum may also attack other Piper species. The major disease is foot-rot caused by the soilborne fungus Phytophthora palmivora. Slow wilt, called "yellow disease”, is associated with Radopholus nematodes.
The fruiting spikes of P. cubeba are collected when the fruits have turned yellow; the fruits are then stripped from the rachis and dried in the sun to turn blackish. Earlier harvesting of green fruits results in too much shrivelling and brownish fruits. Harvesting should be done with care because bruised fruits turn into non-marketable light grey fruits after drying. In India fruiting spikes and parts of the rootstock of P. longum are harvested at the end of the rainy season and dried in the sun. The best time to harvest P. retrofractum is when the spikes are still green but turning slightly reddish at the top. Harvested spikes should be quickly dried in the sun or artificially, because they easily start rotting. Boiling Java long pepper and then spraying it with ash may shorten the drying time to 2 days, otherwise it takes 5 days or longer to dry.
Annual yield of dried fruits per full-grown plant of P. cubeba is about 0.5 kg. P. longum yields from 250 kg/ha in the first year to 1250 kg/ha in the 3rd. Yields then decrease, so after 4-5 years the crop is renewed.
Handling after harvest
Harvested P. cubeba fruits are dried in the sun until they have lost 2/3 of their weight and have become as hard as glass. Dried fruits are hygroscopic and should be stored dry and airtight. P. longum and P. retrofractum spikes are also dried after harvesting and sold as whole fruiting spikes.
Genetic resources and breeding
Germplasm collections are available in Indonesia, Malaysia (Sarawak), India and Brazil. Breeding in Piper is primarily directed towards obtaining foot-rot resistant cultivars in P. nigrum, not towards improving other species.
P. cubeba, P. longum and P. retrofractum are forgotten spices outside South and South-East Asia. They deserve more research attention because their products are still of interest, and the world market for natural flavourings and medicines is growing steadily. They are suitable as a smallholder's crop, but basic agronomic information is still lacking and should be obtained first by applied research.
- Backer, C.A. & Bakhuizen van den Brink Jr, R.C., 1963. Flora of Java. Vol. 1. Wolters-Noordhoff, Groningen, the Netherlands. pp. 168-173.
- Burkill, I.H., 1935. A dictionary of the economic products of the Malay Peninsula. Vol. 2. Crown Agents for the Colonies, London, United Kingdom. pp. 1736-1754.
- Chew, W.L., 1992. Studies in Malesian Piperaceae 2. Blumea 37: 159-164.
- Huber, H., 1987. Piperaceae. In: Dassanayake, M.D. & Fosberg, F.R. (Editors): A revised handbook to the flora of Ceylon. Vol. 6. Amerind Publishing Co., New Delhi, India. pp. 272-300.
- Ilyas, M., 1976. Spices in India. Economic Botany 30(3): 273-280.
- Minagawa, R. & Nakamura, T., 1995. On the origin of the pepper species (Hihatsumodoki) in Ryukyu Islands. Journal of Agricultural Science (Tokyo) 40(2): 100-107.
- Philip, J., Nair, G.S., Premalatha & Sudhadevi, P.K., 1991. Standardisation of vegetative propagation techniques in some of the medicinal plants grown in Kerala. Indian Cocoa, Arecanut and Spices Journal 15(1): 12-14.
- Redgrove, H.S., 1933. Spices and condiments. Pitman & Sons, London, United Kingdom. pp. 174-190.
- Sudiarto, 1992. Budidaya cabe jawa di Kabupaten Lamongan, Jawa Timur [Cultivation of Piper retrofractum in Lamongan Regency, East Java]. Warta Tumbuhan Obat Indonesia 1(3): 8-10.
- Weiss, E.A., 1997. Essential oil crops. CAB International, Wallingford, Oxon, United Kingdom. pp. 362-392.
Sources of illustrations
Piper cubeba: Greshoff, M., 1894. Schetsen nuttige Indische planten [Sketches of useful Indonesian plants]. Koloniaal Museum, Extra Bulletin, Amsterdam. Fig. 37, opposite p. 157 (dried fruit, cross-section dried fruit); Mansfeld, R., 1986. Verzeichnis landwirtschaftlicher und gärtnerischer Kulturpflanzen (ohne Zierpflanzen) [Register of agricultural and horticultural plants in cultivation (without ornamentals)]. Schultze-Motel, J. et al., editors 2nd edition. Vol. 1. Springer Verlag, Berlin, Germany. Fig. 46, p. 239 (fruiting branch, male spike, detail infructescence). Redrawn and adapted by P. Verheij-Hayes.
- D. Utami & P.C.M. Jansen