Phyllanthus emblica (PROSEA)
- Protologue: Sp. Pl. 2: 982 (1753).
- Family: Euphorbiaceae
- Chromosome number: 2n= 98, 104.
- Emblica grandis Gaertner (1790),
- Emblica officinalis Gaertner (1790),
- Emblica arborea Raf. (1838).
- Emblic myrobalan, Indian gooseberry, aonla (En)
- Emblique officinale, groseillier de Ceylan, myrobalan emblic (Fr)
- Indonesia: kimalaka (general), malaka (Sundanese), kemloko (Javanese)
- Malaysia: laka, melaka
- Burma: ta-sha-pen
- Philippines: nelli
- Cambodia: karn lam, kam lam ko, kântûët préi
- Laos: khaam poomz, mak kham pom
- Thailand: ma-khaam pom (general), kan-tot (Khmer, Chantaburi), kam thuat (Ratchaburi)
- Vietnam: chùm ruot, me rừng, chu me (northern), bông ngót (southern).
Origin and geographic distribution
Emblic myrobalan is indigenous to a large area ranging from the southern Himalayas of Nepal and northern India to the south of the Indian subcontinent, Sri Lanka, Burma, Thailand and Indo-China to southern China and Malesia. In Malesia this species occurs naturally in Peninsular Malaysia, Singapore, Sumatra, Borneo, Java, the Lesser Sunda Islands and Ambon. Long ago the species was recorded once in Madagascar. It is widely cultivated for its fruits throughout its natural area of distribution, in India since time immemorial, and also in the West Indies, Japan, the Mascarene Islands and Sri Lanka, where it is doubtfully native.
For several centuries only its fruits were known; they were used medicinally. In 1901 seeds of P. emblica were distributed to early settlers in Florida and to public gardens and experimental stations in e.g. the West Indies, Hawaii and the Philippines. In 1982 seeds were sent to Australia.
Immature fruits are used for tanning in India and Thailand, often in combination with other tanning materials such as chebulic and beleric myrobalans ( Terminalia chebula Retz. and T. bellirica (Gaertner) Roxb., respectively). The bark of the twigs is also of considerable value as tanning material. In combination with the leaves of Carissa spinarum L. (30%) and Anogeissus latifolia Wallich (20%), the twig bark gives a good leather with reddish-brown colour. Stem bark and leaves have also been used locally for tanning.
The leaves are employed for dyeing matting, bamboo wickerwork, silk, and wool brown. The colour becomes black when iron is used as mordant. Matting can be dyed dark colours with a decoction of the bark. In Indonesia, as well as in Indo-China and China, the fruits are used to prepare a black ink and a hair dye. Dried fruits are sometimes used as a shampoo.
The astringent and sour ripe fruits are edible. In Malaysia, Thailand and to a greater extent India the fruits are a delicacy. They are rarely eaten raw; more commonly they are used in cooked food, or as sweetmeat and pickle. They are also made into jam, jelly and syrup. The Akha in northern Thailand use the fruit as a masticatory and to blacken the teeth.
All plant parts are applied medicinally. A decoction of the dried fruits is used in Indonesia to treat bloody diarrhoea. Fruit pulp is smeared on the head to dispel headache and dizziness, caused by excessive heat and fever. In Burma (Myanmar) and Thailand, the fruit juice is used as a laxative and for the treatment of inflamed eyes. In Indo-China, fruits are used to treat diarrhoea, and fruit juice is administered to treat colic and other abdominal disorders. In India, the fruit is valued as an antiscorbutic, refrigerant, diuretic, laxative and antibiotic, and considered useful in the treatment of haemorrhages, diarrhoea, dysentery, anaemia, jaundice, dyspepsia, diabetes, fever, bronchitis and cough. It is used as an ingredient for several medicines of the indigenous Ayurvedic system. Leaf decoctions are used in Malaysia as a febrifuge, and in Thailand for skin diseases. Seeds are applied in India against asthma, bronchitis, and biliousness, whereas flowers are credited with refrigerant and aperient properties. The bark is used in India for the treatment of diarrhoea or as a stomachium for elephants. The root bark is used in Burma (Myanmar) as an astringent and in India, mixed with honey, to treat inflammation in the mouth.
Leaves and fruits are used for animal fodder, whereas leaves can also be applied as green manure. Trees are planted with others to conserve soil. Although the timber may warp and split, it is used for implements and sometimes for building; it can be used to build wells as it is durable under water. The wood is an excellent firewood and provides charcoal of good quality.
Production and international trade
No figures are available either on the production of tanning material or on the production of fruits for consumption.
Fruits, bark and leaves are rich in tannin. Dried pulp of unripe fruits contains 18-30% tannin, sometimes even more (up to 35%). The tannin content of ripe fruits is much lower. The dry stem bark contains only 8-9% tannin, but occasionally as much as 20%. The bark of twigs is usually richer, containing 12-24% tannin on dry weight basis. Leaves may yield 22-28%. The tannins of the fruits belong to the group of gallotannins and ellagitannins, giving on hydrolysis gallic acid in large amounts, ellagic acid in small amounts, and glucose. The tannin of the bark is different; it belongs to the group of proanthocyanidins, giving (+)leucodelphinidin on hydrolysis. It gives a reddish-brown leather with a soft grain which lacks somewhat in flexibility, which is why it is usually mixed with other tanning materials.
The fruit is an extremely rich source of vitamin C, 100 g of juice containing 600-1300 mg of ascorbic acid, sometimes even more. This explains many of the medicinal applications. The tannin in the fruit prevents or retards the oxidation of the vitamin, so that the fruits can be preserved in salt solution or as dry powder while still maintaining their antiscorbutic value. The fruits have diuretic, laxative and purgative activity and also show molluscicidal and antimicrobial properties. The fruit is a rich source of pectin. Fruits of wild plants weigh approximately 5.5 g, cultivated fruits average 28-50 g. Seeds yield about 16% of a brownish-yellow oil. Seed weight is about 570 g/1000 seeds.
The roots are said to be emetic.
The wood is fairly heavy, weighing 720-930 kg/m3, and is hard and close-grained. It has a reddish colour and is liable to split.
- A monoecious, small to medium-sized deciduous tree, rarely up to 25 m tall but usually much shorter, up to 7.5 m, with phyllanthoid branching; trunk often crooked and gnarled, up to 35 cm in diameter; bark thin, smooth, grey, peeling in patches, with numerous bosses from which the leaf-bearing branches arise; branches spreading.
- Cataphylls inconspicuous, scarious, their stipules triangular-ovate; deciduous branchlets (5-)10-25(-30) cm long, with (15-)30-100(-150) leaves;
- Leaves distichous and densely crowded along the apices of lateral twigs, reduced along the main branches, simple and entire, narrowly oblong, 5-25 mm × 1-5 mm, rounded to subcordate and more or less oblique at base, acute or obtuse and mucronate at apex, subsessile, glabrous.
- Flowers fascicled in axils of leaves or fallen leaves, unisexual, the male flowers numerous at base of young twigs, the female flowers solitary and further along the twig; male flowers pedicellate with 6 pale-green 1.5-2.5 mm long perianth-lobes and 3 stamens with entirely connate filaments and anthers; female flowers sessile, with 6 somewhat larger perianth-lobes, a cup-like disk, and a 3-celled superior ovary crowned by 3 styles connate for more than half of their length and deeply bifid at apex.
- Fruit a depressed globose drupe, in wild plants 13-25 mm × 23-30 mm, in cultivated plants often larger (up to 42 mm in diameter), pale green changing to yellow when mature, smooth; stone with 3 subdehiscent compartments, each usually containing 2 seeds.
- Seeds trigonous, 4-5 mm × 2-3 mm, smooth.
Growth and development
The tree is rather slow-growing. Trees usually bear fruits at the earliest when 8 years old, but sometimes they begin to bear when 5-6 years old. In many areas, full-grown trees are rare as a result of slow growth and exploitation.
The tree produces two types of shoots: determinate and indeterminate. The indeterminate shoots are long and provide annual extension growth to the tree. They neither flower nor abscise. The determinate shoots are short, bear flowers, defoliate and abscise. New determinate shoots emerge a few months after abscission of old shoots, and 95% of them will produce flowers. Young shoots are light red, turning green after 2 or 3 days. After about 15 days they produce 2 rows of leaves, and at the same time flowers appear in the axils of the young leaves. Flowering peaks one month after the new shoots appear. In Java this is around August.
Leaves develop completely after fruit set. The development of the leaves probably inhibits flowering. The embryos remain dormant for a period of about 3.5 months. Fertilization is reported to take place within 36 hours following pollination, but the zygote and the endosperm nuclei remain in the uninucleate stage for periods of up to 120 days. The retardation in the development of the fruits correspond with a period of rapid shoot growth, after which shoot growth slows down or stops. It has been suggested that a supra optimal level of auxins translocated from the shoot tips to the embryo causes the dormancy. The fruits are ready for harvesting about 7 months after flowering. They can be retained on the tree for about 3 months without considerable loss in quality or yield.
In some places the tree flowers twice a year. Flowering can also be forced by defoliation by hand, which forces the production of new shoots.
Other botanical information
In literature emblic myrobalan has occasionally been confused with the "true" myrobalans from Terminalia species. However, they only have in common the tannin-yielding fruits. Several Phyllanthus species, including P. emblica, resemble legumes. The feathery leafy and deciduous branchlets are identical to pinnate leaves (for instance, those of Parkia spp.). The cultivars cultivated as fruit trees in India include "Banarasi", "Chakla", "Desi", "Francis", "Kanchan", and "Krishna".
Emblic myrobalan is a light-demanding species which is often common in grassy areas, brush and village groves. In Java it is also found in teak forests, in Peninsular Malaysia it is frequent in lowland forests. The species is photosensitive, only producing flowers at a daylength between 12 and 13.5 hours.
The tree is fire-resistant, and is one of the first trees to recover after a fire. It occurs from almost sea-level to 1200 m altitude in north-western Thailand and Indonesia (Java); in the sub-Himalayan region even up to 1500 m. Emblic myrobalan is slightly tolerant of alkaline soils. In Indonesia it is found in very dry areas but not along the coasts. However, some cultivars are sensitive to drought, and also to frost.
Propagation and planting
In the past, propagation was usually by seeds. For extensive production and selection, vegetative propagation is necessary. A high percentage of rooting (84%) has been reported from semi-hard wood cuttings collected from the middle portions of invigorated shoots of young trees and planted in beds at a temperature of about 33°C. Budding and softwood grafting may also give good results. In the early stages of growth, copious watering in the dry season and some weeding are necessary.
The tree coppices well and pollards moderately well. Coppiced shoots grow particularly vigorously, and coppicing is considered the system most suitable for the production and collection of tanbark on a commercial scale. Usually plantations need much weeding because the canopy is not closed by the thin crowns.
Diseases and pests
In India several diseases have been reported. A dieback disease is caused by Botryodiplodia theobromae, and seedlings are susceptible to a root-rot disease caused by Rhizoctonia solani. Trees may be affected by rusts such as a leaf rust caused by Phakopsora phyllanthi and a ring rust caused by Ravenelia emblica.
Indarbela spp., bark-eating caterpillars, damage trees. The fruits are susceptible to rot diseases as a result of infection by Penicillium spp., Glomerella cingulata, Phoma putaminum, and Aspergillus niger.
The bark of shoots of less than 5 cm diameter is used to obtain a good tannin. Usually branches can be coppiced every 2 years. For use in tanning, the fruits should be harvested unripe.
The fruiting season is exceptionally long since the ripe fruits may be retained for several months on the tree without significant loss of quality. Because of this, a long period is available for picking the fruits for consumption.
The average annual yield of wild trees in India is about 15 kg of fruit per tree. Some cultivars may yield over 25 kg of fruit.
Handling after harvest
Quickly-dried bark contains much more tannin than slowly-dried bark. Therefore it has been recommended to dry the bark rapidly in the sun. The stone of unripe fruits should be removed and the remaining flesh dried and ground to prepare a tanning material.
Fresh fruits are not palatable because of their astringent and sour taste. The astringency can be removed by steeping the fruits in brine for a few days. Fruits are often preserved by splitting, removing the stone, putting the segments into a solution of 42% glycerol, 42% sucrose, water and preservatives, then heating to 90°C for 3 minutes. The fruits are allowed to equilibriate in the solution for two days at 2°C, then they are drained and packed into containers. Fruits preserved in this way remain acceptable for about 2 months at room temperature, and much longer when cooled, while the ascorbic acid content drops slowly.
Marketability of fresh fruits is improved by a combined treatment with wax emulsion and 10 mg/l morphactin. This delays browning and reduces the infection rate from Aspergillus and Penicillium species. For medicinal purposes, fruits are simply dried.
Emblic myrobalan is a tree which deserves more attention. As a tannin and dye-yielding species it has interesting aspects because it could be a regular supplier of tanning and dyeing material by coppicing the tree or harvesting young fruits. Trees are not killed at harvest as is so often the case with species yielding tanbark.
Experiments in Indonesia show that this species is not easy to cultivate on a large scale. It is rather slow-growing and needs much weeding. New experiments of methods of cultivation might be worthwhile. Selection for large edible fruits is normally not compatible with selection for fruits with high tannin content. Combined selection for tanning and medicinal purposes seems to be possible. Emblic myrobalan has great therapeutic potential.
- Morton, J.F., 1987. Fruits of warm climates. Creative Resource Systems Incorporated, Winterville, USA. pp. 213-217.
- Parmar, C. & Kaushal, M.K., 1981. Wild fruits of the Sub Himalayan Region. Kalyami Publishers, New Delhi. pp. 26-30.
- Ram, S., 1982. Induction of off-season flowering in Aonla (Emblica officinalis Gaertn.) trees. Progressive Horticulture (India) 14(2-3): 180-183.
- Sastri, B.N. (Editor), 1952. The wealth of India. Raw materials. Vol. 3. Council of Scientific and Industrial Research, New Delhi. pp. 168-170.
- Singh, I.S., Pathak, R.K., Simon, J.E., Mathe, A. & Craker, L.E., 1987. Evaluation of Aonla varieties for processing. Sixth international symposium on medicinal and aromatic plants. Acta Horticulturae (Netherlands) No 208. pp. 173-177.
- Soetisna, U. & Hidajat, E., 1977. Kimalaka (Phyllanthus emblica L.) yang jarang dikenal [The rarely known emblic myrobalan, Phyllanthus emblica L.]. Buletin Kebun Raya 3(3): 77-80.
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- A.J.J. van Schaik-van Banning
- F.L. van Holthoon