Rubia cordifolia (PROSEA)
- Protologue: Syst. nat. ed. 12,3 (add.): 229 (1768).
- Family: Rubiaceae
- Chromosome number: 2n= 22 (44, 66)
- Rubia munjista Roxb. (1820),
- Rubia javana DC. (1830),
- Rubia mitis Miq. (1867).
- Indian madder (En)
- Indonesia: letah meong (Sundanese), kletak (Javanese)
- Philippines: kamagut, mankit (Igorot), pantig-pantig (Bagobo)
- Vietnam: thiên can.
Origin and geographic distribution
Indian madder has an extremely large area of distribution, ranging from Africa through Central Asia to the Soviet Union, India, Japan, China, Indo-China, Malaysia (Sabah), the Philippines, parts of Indonesia (Sumatra, Java), and northern Australia.
Extracts from the root and the stem have long been used to dye coarse cotton fabrics, blankets and carpets. The orange or red colour obtained is brighter than that from madder root (Rubia tinctorum L.), though less permanent. The colouring power of R. cordifolia is less than that of R. tinctorum. To dye a piece of cloth, it is steeped in an infusion of the root or stem in water, being mordanted with alum. As a dye, Indian madder has largely been replaced, first by madder root, later by synthetic dyes.
Indian madder has several medicinal uses, for instance in Ayurvedic and Chinese medicine. Roots are credited with astringent and antidysenteric properties. They are said to be active against Staphylococcus aureus and are made into a paste, which is applied to ulcers and skin infections. A decoction of the leaves and stems is used as a vermifuge e.g. in the Philippines. An extract of the plant is used as one of the components of a medicine used against nasal infections. The leaves of the plant are eaten in Java as a side dish with rice (lalab).
The colouring matter in the roots is a mixture of alizarin (1,2-dihydroxy-anthraquinone), purpurin (1,2,3-trihydroxy-anthraquinone), purpuroxanthin (1,3-dihydroxy-anthraquinone) and munjistin (1,3-dihydroxy-2-methoxy-anthraquinone). Small amounts of several other anthraquinones and derivatives have been reported.
- An extremely variable species. Climbing or creeping herb up to 10 m long. Rootstock perennial, roots long, cylindrical, flexuose with thin red bark. Stem with long internodes, quadrangular, sometimes prickly or hispid, often glabrous.
- Leaves simple, (2-)4(-8) together in whorls, leaf blade cordate to (narrowly) ovate, 2.5-10 cm × 1-4 cm, veins 3-9-palmate, cordate or rounded at base, acute or acuminate at apex, entire, surface smooth or retrorsely scabrid or hairy or strigose; petiole usually long, 5-8 cm, sometimes as short as 0.5 cm.
- Flowers in axillary and terminal cymose, trichotomously branching, long-peduncled panicles, 3.5-4.5 mm in diameter, with colour variable from greenish-white to purple-red, (4-)5-merous; stamens epipetalous; ovary inferior, 2-celled, styles 2.
- Fruit a globose or 2-lobed berry, 4-5 mm × 3.5-5 mm, blueish-black, sometimes red or purple, 1-2-seeded.
Considering the entire area of distribution, the variability of R. cordifolia is extraordinary. Attempts to split the species into several taxa have failed, and much experimental taxonomic work would be needed to unravel the systematics of this species and its allies. Subdivisions of the species have been based on variable characters such as the nature of the surface of stems and leaves (prickly to glabrous), shape of the leaves, colour of flowers and fruits, and epigeal or hypogeal germination.
A form, described as var. khasiana Watt, is reported to contain more dye than other forms. It has mostly 5 veins and a smooth surface of the leaves, and occurs in north-eastern India, Bangladesh, Nepal and Sikkim. R. tinctorum, the European madder or madder root and R. sikkimensis Kurz are related species, containing similar dye components.
R. cordifolia should not be confused with Oldenlandia umbellata L., also called Indian madder and containing very similar dyeing components.
The vast area over which R. cordifolia occurs indicates its adaptability. In South-East Asia it occurs mostly in humid areas, 500-2500 m above sea-level, mostly in secondary vegetation.
Handling after harvest
Roots and stems are collected, apparently exclusively from the wild, dried and chopped into small pieces. These are mixed with water to prepare the dye.
R. cordifolia has at present nearly lost its importance as a dye-producing plant. However, its pharmaceutical importance seems to be increasing. The possibility of using cell cultures to produce anthraquinones for pharmaceutical purposes is being tested.
- Backer, C.A. & Bakhuizen van den Brink, R.C., 1965. Flora of Java. Vol. 2. Noordhoff, Groningen, the Netherlands. p. 356.
- Chadha, Y.R. (Editor), 1972. The wealth of India. Raw materials. Vol. 9. Publications & Information Directorate, Council of Scientific and Industrial Research, New Delhi. pp. 82-85.
- Deb, D.B. & Malick, K.C., 1968. Revision of the genus Rubia L. in India and adjoining regions. Bulletin of the Botanical Survey of India 10: 1-16.
- Suzuki, H. & Matsumoto, T., 1988. Anthraquinone production by plant cell culture. In: Bajaj, Y.P.S. (Editor): Medicinal and Aromatic Plants I. Springer Verlag, Berlin. pp. 237-250.