1413

3: Dye and tannin-producing plants

Morinda citrifolia L.

Sp. Pl. 1: 176 (1753).

RUBIACEAE

2n = 44

Morinda bracteata Roxb. (1814), Morinda litoralis Blanco (1845).

Indian mulberry (En). Morinde (Fr). Indonesia: mengkudu (Javanese), bengkudu (Minahasa, Gorontalo), cangkudu (Sundanese). Malaysia: mengkudu besar, mengkudu jantan. Philippines: tumbong-aso (Tagalog), bangkuro (Bisaya), apatot-nga-basit (Ilokano). Burma: al. Cambodia: nhoër srôk, nhoër thôm'. Laos: nhoo baanz. Thailand: yo ban. Vietnam: nhàu.

Indian mulberry is a native of Queensland (Australia). It may have been distributed by man and carried westwards into the Indian Ocean by sea currents, reaching the Seychelles, and similarly into the Pacific between 30°N and 30°S latitude, reaching the Marquesas, Hawaii, and Easter Island. It is present throughout South-East Asia both wild and cultivated. It often occurs wild in coastal zones. It is naturalized in the Caribbean region.

Before the introduction of synthetic dyes (e.g. alizarin) the red dye from the rootbark of Indian mulberry was important. In the late 19th Century, there were plantations in coastal areas of northern Java and adjoining islands. Nowadays, single trees are encouraged or cultivated in gardens mainly for medicinal purposes. Cultivation for the dye is restricted to areas where traditional textile dyeing is still important, e.g. in the production of high quality batik on Java.
Most parts of the tree have been widely used medicinally since ancient times. In Vietnam roots serve to treat stiffness and tetanus and have been proven to combat arterial tension. Elsewhere they are used as febrifuges and as a tonic. The bark is used as a tonic and as an antiseptic on skin lesions, ulcers and wounds. The leaves are used to treat dysentery, diarrhoea, colic, nausea and convulsions and as a febrifuge, tonic and antiseptic. The fruits are used as a diuretic, a laxative, an emollient and as an emmenagogue, for asthma and other respiratory problems, as a treatment for arthritic and comparable inflammations, in cases of leucorrhoea and sapraemia and for maladies of inner organs. Roots, leaves and fruits may have anthelmintic properties. In traditional medicine the parts used are administered raw or as juices and infusions or in ointments and poultices.
Despite the smell of putrid cheese when ripe, the fruits are eaten raw or prepared, as are the leaves. The fruit pulp can be used to cleanse hair, iron and steel. The wood splits excessively in drying and its uses are restricted to fuel and poles. In Malaysia and Thailand the tree is used as a support for pepper plants.

The basis of the morindone dyeing matter, called Turkish red, is the hydrolysed (red) form of the glycoside morindin. This is the most abundant anthraquinone which is mainly found in the rootbark which reaches a concentration of 0.25—0.5% in fresh bark in 3—5 years. It is similar to that found in Rubia tinctorum L. and to synthetic alizarin. The curative properties of the plant parts are ascribed to the presence of medicinally active anthraquinone derivates. The fruit contains rancid smelling capric acid and unpleasant tasting caprylic acid. It is thought that antibiotically active compounds are present. The nutritional value of the fruit and leaves is considerable. The leaves are a rich source of vitamin A.

An evergreen shrub or small crooked tree with a conical crown, 3—8(—10) m tall, with a deep taproot; bark greyish or yellowish-brown, shallowly fissured, glabrous; branchlets quadrangular. Leaves opposite and simple, elliptic-lanceolate, (10—)15—50 cm x 5—17 cm, entire, acute to shortly acuminate at apex, cuneate at base, pinnately nerved, glabrous; petioles 0.5—2.5 cm long; stipules variable in size and shape, broadly triangular. Inflorescences globose heads, 1—4 cm long peduncled, in axils of stipules opposite normally developed leaves; flowers bisexual, fragrant; corolla funnel-shaped, up to 1.5 cm long, white; stamens inserted on the mouth of the corolla; stigma bilobed. Fruit an ovoid syncarp of red-brown, pyramidal, 2-seeded drupes, 3—10 cm x 2—3 cm, yellow-white. Seeds black, with hard albumen and distinct air chamber.

The seed remains viable for at least 6 months. Germination is 3—9 weeks after sowing. Plant growth is 1.2—1.5 m in 6 months. Flowering and fruiting start in the third year and continue throughout the year. Maximum age is at least 25 years.

Morinda citrifolia is sometimes subdivided into two varieties: var. citrifolia and var. bracteata (Roxb.) Hook.f. The latter has calyx-limbs with 1—2 leaflike, linear-lanceolate lobes ca. 1—1.5 cm long; the stem is straighter and the leaves are smaller than var. citrifolia.

Indian mulberry is commonly found up to altitudes of 1500 m in humid and seasonal climates of the region, with an estimated annual rainfall of 1500—3000 mm or more. In areas where the plant is cultivated, the soil is usually well structured and of volcanic origin (Java), but it may be poor and ferralitic (Cambodia). In the wild the plant also appears on infertile, degenerated soils, sometimes badly drained or with a very low water-retention capacity and a deep water table.
The species occurs in evergreen, (semi-)deciduous to more or less xerophytic formations, often typically littoral vegetations. It also occurs in pioneer and secondary vegetation after cultivation and bush fires (Cambodia), deforestation or volcanic activity (Krakatau). It is persistent and very tolerant. The ability of the seeds to float explains its wide distribution and occurrence on many seashores. Inland distribution agents are fruit-eating bats and birds.

Indian mulberry is propagated by seeds which should be sown in nursery beds. After germination, seedlings are transplanted at ca. 1.2 m x 1.2 m in well-tilled soil.

Weeding is carried out at least twice and starts about 1 month after transplanting. No maintenance is needed after the first year. Intercropping with cereals and perennials is possible (e.g. shade in coffee).

High-yielding bark may be expected after 3—5 years. The roots are dug out, cleaned in water, and the bark removed.

Yield of bark is reported to be 500—1000 kg/ha, containing about 0.25% morindin.

The bark is ready for use after drying in the sun for several days. In the complex cold-dyeing process of the Java batik, cloth is prepared with an alkalic emulsion, 4 times a day, for 10 days. The bark is pounded with jirak bark (Symplocos fasciculata Zoll.), mashed with water and applied to the cloth by hand. This is repeated for 5 days. The cloth acquires a clear red, wash-fast colour. Elsewhere, the same dyeing principle is used. Jirak bark serves as a mordant. It is rich in aluminium salts.

The species is diminishing in its natural habitat. It is not very likely to be endangered by serious genetic erosion given its pioneering character, its natural variation and its wide, though small-scale, cultivation. There are no reported germplasm collections.

Renewed interest in natural dyes and medicine in Indonesia and elsewhere may revive bark production. Evaluation of fruits and leaves for nutritional purposes is recommended.

Abbot, I.A. & Shimazu, C., 1985. The geographic origin of plants most commonly used for medicine by Hawaiians. Journal of Ethnopharmacology 14(2/3): 213—222.
Haake, A., 1984. Javanische Batik: Methode, Symbolik, Geschichte. Verlag M. & H. Schaper, Hannover, Germany. pp. 17—23, 94—108.
Hidayat, E., 1978. Pohon Cenkudu (Morinda citrifolia L.) dan manfaatnya khususnya sebagai obat tradisional [M. citrifolia L. and its special use as a traditional drug]. Buletin Kebun Raya 3(4): 141—144.
Martin, F.W. & Ruberté, R.M., 1980. Techniques and plants for the tropical subsistence farm. United States Department of Agriculture (USDA). Agricultural Reviews and Manuals ARM-s-8. 56 pp.

J.J. Groenendijk

Groenendijk, J.J., 1991. Morinda citrifolia L.. In: Lemmens, R.H.M.J. and Wulijarni-Soetjipto, N. (Editors): Plant Resources of South-East Asia No 3: Dye and tannin-producing plants. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea