"There is another fruit called Carambola," wrote the Dutch traveler Linschoten in 1598, "which hath 8 corners, as bigge as a smal aple, sower in eating, like unripe plums, and most used to make Con-serues." The Chinese and the Hindus eat the carambola when green as a vegetable, when ripe as a dessert. It is widely distributed in the tropics, but in America it is not so highly esteemed as in the Orient.
The tree is small, handsome, and grows up to 30 feet in height. It has compound leaves composed of two to five pairs of ovate or ovate-lanceolate leaflets, rounded at the base and acute to acuminate at the apex, 1 1/2 to 3 inches long, glabrous, light green above and glaucous below. The small white or purplish flowers are borne in short racemes from the bark of the young and old branches. The petals are five; the stamens ten, but five are without anthers. The fruit is oval or elliptic in outline, translucent yellow or pale golden brown in color, 3 to 5 inches long, and three-, four-, or five-ribbed longitudinally, so that a cross-section is star-shaped. "It contains a clear watery pulp," writes W. E. Safford, "astringent when green and tasting like sorrel or green gooseberries, but pleasantly acid when ripe, or even sweet, with an agreeable fruity flavor, and a strong perfume like that of the quince"
Fig. 55. A flowering and fruiting branch of carambola (Averrhoa Carambola), an Asiatic fruit sometimes cultivated in tropical America. (X 1/2)
While the native home of this species is not definitely known, it is believed to be indigenous to the Malayan region, whence it was early brought to America. It is now cultivated in southern China, and from there westward to India. Safford states that it grows in Guam, but is not common. It also grows in the Philippines and in Hawaii. In America it is most abundant in Brazil, where it was doubtless introduced by the Portuguese. It does not grow in California, but succeeds in southern Florida. E. N. Reasoner has a handsome specimen in his tropical fruit shed at Oneco, near Bradentown, a place which would be too cold for the species were it not given some protection during the winter. It is rare on the lower east coast of Florida.
The name carambola is said to have come from Malabar, and was early adopted by the Portuguese. In upper India the fruit is called kamranga or kamrakh. The presence of a Sanskrit name, karmara, and the accounts of early writers, indicate that the plant was known in India before the time of European colonization. The Chinese are said to call the fruit yongt'o or foreign peach. In the Philippines it is termed balimbing as well as carambola; in Guam bilimbines.
The fruits, when fully ripe, are eaten out of hand, or they may be stewed. When slightly unripe they are used for jelly and pickles. Like the bilimbi, the carambola contains potassium oxalate, and for this reason the unripe fruit is used in dyeing and to remove iron-rust. In southern China caram-bolas are preserved in tin and exported to other countries. An analysis made in Hawaii by Alice R. Thompson shows the ripe fruit of the sweet variety to contain: Total solids 8.22 per cent, ash 0.42, acids 0.78, protein 0.71, total sugars 3.40, fat 0.75, and fiber 1.23.
In its climatic requirements the tree may be considered tropical. It withstands very little frost and when young is injured by temperatures above the freezing-point. It prefers a warm moist climate and a deep rich soil, but it can be grown successfully on sandy soils and heavy clays, and in northern India it thrives where the climate is dry. Cold is the limiting factor in California and Florida; in the latter state it may succeed from Palm Beach southwards, but plants have often failed to grow at Miami. When young the carambola is delicate and requires careful attention.
Safford states that the tree is long-lived and a constant bearer, producing, in Guam, several crops a year. Father Tavares writes of its behavior in Brazil: "During the entire year it loads itself with successive crops of flowers and fruits, except for a short period when it is devoid of foliage."
Propagation is readily effected by means of seeds, and P. J. Wester has shown that budding is successful. He states that budwood should be beyond the tender stage, but not so old that it is brittle. It should not be used if the petioles have fallen. The buds should be cut an inch in length, and inserted in inverted T-incisions, the operation of budding being essentially the same as with the avocado.
No horticultural varieties of the carambola are yet established. Sweet and sour seedling forms are sometimes recognized.