Cassia auriculata (PROSEA)
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Introduction |
- Protologue: Sp. Pl. 1: 379 (1753).
- Family: Leguminosae
- Chromosome number: 2n= 14, 16, 28
Synonyms
- Cassia densistipulata Taubert (1895).
Vernacular names
- Avaram, tanner's Cassia (En)
- Malaysia: gelam tangedu
- Burma: peikthingat.
Origin and geographic distribution
Avaram is a native of India, Burma, and Sri Lanka. It is cultivated in India, and, on a small scale, in Sri Lanka. The species has been successfully introduced in West Africa and East Africa. It has been suggested to be indigenous in Tanzania, but an early introduction and naturalization seems more likely. It was also tried in Java, where it failed.
Uses
Avaram is a multipurpose plant. The bark can be used for tanning heavy hides and also goat and sheep skins, giving a buff-coloured leather of good quality, which tends to darken on exposure to light. To prevent this the leather is often finished by a tannage using myrobalans from Terminalia chebula Retz. The bark fibre can be made into rope, and a fermented mixture of pounded bark and dissolved molasses serves as an alcoholic beverage in some parts of India. In Sri Lanka the leaves are sometimes used to make tea. Avaram does not reach a volume adequate for timber, but sometimes handles of small tools are made from the wood. It is used for revegetating erodible soils and as a green manure, and also proved very effective in reclaiming sodic soils which have been dressed with gypsum. In times of food scarcity the pods, leaves and flowers are used as a vegetable. Avaram is suited as fodder for goats and cattle and for feeding silkworm, but poisonous substances have been reported. Medicinal uses are numerous. The roots and bark are astringent and are used for gargles, as an alterative, and to cure skin diseases. A decoction of the flowers and the seeds is recommended for diabetes, seeds are used to cure eye diseases. Leaves and fruits serve as anthelmintic. Sometimes avaram is cultivated as an ornamental.
Production and international trade
Avaram was a major source of tannin in India, the most important areas of production being Madras, Hyderabad, and Mysore. In the past production was as high as 50 000 t of dried bark per year. But syntans and imported barks, especially of black wattle ( Acacia mearnsii De Wild.) from southern Africa, have largely taken avaram's place. Outside India, avaram has never been cultivated on a large scale.
Properties
The bark contains 15-22% of tannin on a dry weight basis in plants over three years old. Saponin and sennapikrin are reported from the roots. The bark, flowers, and seeds contain pyrrolizidine alkaloids, suspected of hepatotoxic properties. Beta-sitosterin is found in the seed.
Botany
- Shrub, 2-5(-7.5) m tall, trunk up to 20 cm in diameter. Bark thin, brown, lenticellate.
- Leaves pinnate, with 10-14 cm long petiole and rachis provided with a gland between each pair of leaflets; stipules persistent, large and leafy; leaflets 6-13 pairs, oblong-elliptic to obovate-elliptic, 10-25(-35) mm × 5-12 mm, rounded and mucronate at apex.
- Flowers in corymbose, terminal panicles, which consist of aggregated, 2-8-flowered racemes; sepals 5, rounded at apex; petals 1.5-3 cm long, yellow; stamens 10, the 3 lower ones largest and fertile, others usually sterile.
- Fruit an oblong-linear pod, 5-12(-18) cm × 1-2 cm, indehiscent, usually 10-20-seeded.
- Seeds with a distinct areole on each face.
In India avaram usually shows two bursts of flowers, one in the early monsoon and another in the late monsoon.
Ecology
In the natural or naturalized state, avaram is found in woodland and wooded grassland. It usually grows wild in dry regions with a minimum annual precipitation of 400 mm, but it can also tolerate wet climates with an annual precipitation up to 4300 mm. The mean annual temperature can vary from 16 to 27.5°C. Avaram tolerates many types of soil, but prefers fairly rich, well-drained soils. It needs full sun.
Agronomy
Avaram is easy and cheap to raise and is propagated by seed and by stem cuttings. For quick germination seeds are scarified and held in running water. The seedlings are fairly resistant to desiccation. Stem cuttings are planted 5-12.5 cm apart in rows. Thinning is necessary after the first year. Limed soil is reported to increase the amount of tannin. No serious pests or diseases are reported, although aphids and mites have been found feeding on the plant. In the third year the twig bark can be stripped. The bark is sun dried in small pieces which are directly used by the tanners. Coppiced bushes can be harvested annually. The yield averages 1500 kg of sun-dried bark per ha in a plantation of ca. 9000 plants/ha.
Prospects
Avaram is easy to grow and has numerous uses. It could be an interesting plant in the drier parts of South-East Asia, especially because of its good tanning properties, and for revegetating barren tracts.
Literature
- Bhatnagar, S.S. (Editor), 1950. The wealth of India. Raw materials. Vol. 2. Delhi. pp. 96-97.
- Duke, J.A., 1981. Handbook of legumes of world economic importance. Plenum Press, New York and London. pp. 45-47.
- Howes, F.N., 1962. Tanning materials. In: von Wiesner, J. (Editor): Die Rohstoffe des Pflanzenreichs. 5th ed. J. Cramer, Weinheim, Germany. p. 194.
- Purseglove, J.W., 1974. Tropical crops. Dicotyledons 2. Longman, London. p. 204.
Authors
Maman Rahmansyah
