In addition to the usefulness of its fruit, the tamarind has the advantage of being one of the best ornamental trees of the tropics. It is particularly valued in semi-arid regions, where it grows luxuriantly if supplied with water at the root. From India to Brazil, its huge dome-shaped head of graceful foliage enlightens many a dreary scene.
The fruit became known in Europe in the Middle Ages. Marco Polo mentioned it in 1298, but it was not until Garcia d'Orta correctly described it in 1563 that its true source was known; it was thought at first to be produced by an Indian palm. The New England sea-captains who traded with the West Indies in the eighteenth and nineteenth centuries frequently brought the preserved fruit to Boston from Jamaica and other islands, but in recent years it has become scarcely known in the United States. In Arabia and India, however, it is a product of considerable importance.
When grown on deep rich soils the tree may attain to 80 feet in height, with a trunk 25 feet in circumference. The small pale green leaves are abruptly pinnate, with ten to twenty pairs of opposite, oblong, obtuse leaflets, soft and about \ inch long. The pale yellow flowers, which are borne in small lax racemes, are about 1 inch broad. The petals are five, but the lower two are reduced to bristles. The fruit is a pod, cinnamon-brown in color, 3 to 8 inches long, flattened, and 1/2 to 1 inch in breadth. Within its brittle covering are several obovate compressed seeds surrounded by brown pulp of acid taste.
The tamarind is believed to be indigenous to tropical Africa and (according to some authors) southern Asia. It has long been cultivated in India and it was early introduced into tropical America. It succeeds in southern Florida and has been grown in that state as far north as Manatee, where a large tree was killed by the freeze of 1884.
Fig. 56. The tamarind (Tamarindus in-dica), a leguminous fruit-tree whose brown pods contain an acid pulp used in cooking, and to prepare refreshing drinks. (X 1/2)
It is not sufficiently hardy to be grown in any part of California.
Yule and Burnell say: "The origin of the name is curious. It is Arabic, tamar-u'l-Hind, 'date of India,' or perhaps rather in Persian form, tamar-i-Hindi. It is possible that the original name may have been thamar, 'fruit' of India, rather than tamar, 'date.'" In French it is tamarin, in Spanish and Portuguese tamarindo.
The fruit is widely utilized in the Orient as an ingredient of chutnies and curries and for pickling fish. In medicine, it is valued by the Hindus as a refrigerant, digestive, carminative, laxative, and antiscorbutic. Owing to its possession of the last-named quality, it is sometimes used by seamen in place of lime-juice. With the addition of sugar and water it yields a cooling drink or refresco, especially well known in Latin America. In some countries tamarinds are an important article of export. In Jamaica the fruit is prepared for shipment by stripping it of its outer shell, and then packing it in casks, with alternate layers of coarse sugar. When the cask is nearly full, boiling sirup is poured over all, after which the cask is headed up. In the Orient the pulp containing the seed is pressed into large cakes, which are packed for shipment in sacks made from palm leaves. This product is a familiar sight in the bazaars, where it is retailed in large quantities; it is greatly esteemed as an article of diet by the East Indians and the Arabs. Large quantities are shipped from India to Arabia.
The pulp contains sugar together with acetic, tartaric, and citric acids, the acids being combined, for the most part, with potash. In East Indian tamarinds citric acid is said to be present in about 4 per cent and tartaric about 9 per cent. The following analysis has been made in Hawaii by Alice R. Thompson : Total solids 69.51 per cent, ash 1.82, acids 11.32, protein 3.43, total sugars 21.32, fat 0.85, and fiber 5.61. Commenting on this analysis, Miss Thompson says: "The tamarind is of interest because of its high acid and sugar content. It is supposed to contain more acid and sugar than any other fruit. The analysis reported by Pratt and Del Rosario shows the green tamarind to contain little sugar, but the sugar increases very greatly on ripening."
The tree delights in a deep alluvial soil and abundant rainfall. Lacking the latter, it will make good growth if liberally irrigated. The largest specimens are found in tropical regions where the soil is rich and deep. On the shallow soils of southeastern Florida the species does not attain to great size. When small it is very susceptible to frost, but when mature it will probably withstand temperatures of 28° or 30° above zero without serious injury. It is usually given little cultural attention, and is not grown as an orchard tree.
Propagation is commonly by means of seeds. These can be transported without difficulty, since they retain their viability for many months if kept dry. They are best sprouted by planting them \ inch deep in light sandy loam. The young plants are delicate and must be handled carefully to prevent damping-off. P. J. Wester has found that the species can be shield-budded in much the same manner as the avocado and mango. He says: "Use petioled, well-matured, brownish or grayish budwood; cut the buds one inch long; age of stock at point of insertion of bud unimportant."
Seedling trees are slow to come into bearing. A mature tree is said to produce, in India, about 350 pounds of fruit a year.
Little is known of the insect pests which attack the tamarind. H. Maxwell-Lefroy mentions two, Caryoborus gonagra F., and Charaxes fabius Fabr., the latter a large black, yellow-spotted butterfly whose larva feeds on the leaves. Both these insects occur in India.
Thomas Firminger speaks of three varieties of tamarind which are grown in India, but does not know whether they can be depended on to come true from seed. M. T. Masters, in the "Treasury of Botany," states that the East Indian variety has long pods, with six to twelve seeds, while the West Indian variety has shorter pods, containing one to four seeds. Seedlings undoubtedly show considerable variation in the size and quality of their fruit, which accounts for the different "varieties" which have been noted by many writers. Since none of these has yet been propagated vegetatively, they are of little horticultural importance.