Except for the fact that a few trees have been planted in the West Indies and elsewhere, and that P. J. Wester has shown that it can readily be budded (thus paving the way for its improvement), the durian occupies the same position to-day which it held when first observed by Europeans in the fifteenth century, - that of a semi-cultivated fruit of great importance to the inhabitants of the Malayan region.
Its tardy dissemination has probably been due to the perishable nature of its seeds, making it difficult to carry the species from one part of the tropics to another. It must be admitted, also, that the fruit is not one which has invariably met with a favorable reception from Europeans. Because of its strong disagreeable odor many do not like it, but others become extremely fond of it.
In its native home the durian becomes a large tree. It has obovate-oblong leaves 6 to 7 inches long, leathery in texture, shining on the upper surface and scaly on the lower. The flowers, which are produced in cymes, have a bell-shaped five-lobed calyx and five oblong petals. The fruit is oval in form, 6 to 8 inches long, covered externally with short woody protuberances. It is five-valved, and within each compartment are several seeds surrounded by clear pale brown custardlike pulp of strong gaseous odor and rich bland taste. The following description by a distinguished durian-eater, Alfred Russel Wallace, 1 gives an excellent idea of this remarkable fruit:
"The banks of the Sarawak River are everywhere covered with fruit trees, which supply the Dyaks with a great deal of their food. The Mangosteen, Lansat, Rambutan, Jack, Jambou, and Blimbing, are all abundant; but most abundant and most esteemed is the Durian, a fruit about which very little is known in England, but which both by natives and Europeans in the Malay Archipelago is reckoned superior to all others. The old traveller Linschott, writing in 1599, says: - 'It is of such an excellent taste that it surpasses in flavor all the other fruits of the world, according to those who have tasted it.' And Doctor Paludanus adds: - "This fruit is of a hot and humid nature. To those not used to it, it seems at first to smell like rotten onions, but immediately they have tasted it they prefer it to all other food. The natives give it honorable titles, exalt it, and make verses on it.' When brought into a house the smell is often so offensive that some persons can never bear to taste it. This was my own case when I first tried it in Malacca, but in Borneo I found a ripe fruit on the ground, and, eating it out of doors, I at once became a confirmed Durian eater.
"The Durian grows on a large and lofty forest tree, somewhat resembling an elm in its general character, but with a more smooth and scaly bark. The fruit is round or slightly oval, about the size of a large coconut, of a green color, and covered all over with short stout spines, the bases of which touch each other, and are consequently somewhat hexagonal, while the points are very strong and sharp. It is so completely armed, that if the stalk is broken off it is a difficult matter to lift one from the ground. The outer rind is so thick and tough, that from whatever height it may fall it is never broken. From the base to the apex five very faint lines may be traced, over which the spines arch a little; these are the sutures of the carpels, and show where the fruit may be divided with a heavy knife and a strong hand. The five cells are satiny white within, and are each filled with an oval mass of cream-colored pulp, imbedded in which are two or three seeds about the size of chestnuts. This pulp is the eatable part, and its consistence and flavor are indescribable. A rich butterlike custard highly flavored with almonds gives the best general idea of it, but intermingled with it come wafts of flavor that call to mind cream-cheese, onion-sauce, brown sherry, and other incongruities. Then there is a rich glutinous smoothness in the pulp which nothing else possesses, but which adds to its delicacy. It is neither acid, nor sweet, nor juicy, yet one feels the want of none of these qualities, for it is perfect as it is. In fact to eat Durians is a new sensation, worth a voyage to the East to experience.
1 The Malay Archipelago.
"When the fruit is ripe it falls of itself, and the only way to eat Durians in perfection is to get them as they fall; and the smell is then less overpowering. When unripe, it makes a very good vegetable if cooked, and it is also eaten by the Dyaks raw. In a good season large quantities are preserved salted, in jars and bamboos, and kept the year round, when it acquires a most disgusting odor to Europeans but the Dyaks appreciate it highly as a relish with their rice. There are in the forest two varieties of wild Durians with much smaller fruits, one of them orange-colored inside; and these are probably the origin of the large and fine Durians, which are never found wild. It would not, perhaps, be correct to say that the Durian is the best of all fruits, because it cannot supply the place of the subacid, juicy kinds, such as the orange, grape, mango, and mangosteen, whose refreshing and cooling qualities are so wholesome and grateful; but as producing a food of the most exquisite flavor it is unsurpassed. If I had to fix on two only, as representing the perfection of the two classes, I should certainly choose the Durian and the Orange as the king and queen of fruits.
"The Durian is, however, sometimes dangerous. When the fruit begins to ripen it falls daily and almost hourly, and accidents not infrequently happen to persons walking or working under the trees. When a Durian strikes a man in its fall, it produces a dreadful wound, the strong spines tearing open the flesh, while the blow itself is very heavy; but from this very circumstance death rarely ensues, the copious effusion of blood preventing the inflammation which might otherwise take place. A Dyak chief informed me that he had been struck down by a Durian falling on his head, which he thought would certainly have caused his death, yet he recovered in a very short time."
The area in which the durian is indigenous has not been determined with certainty. The species is generally believed to be native to Borneo and other islands of the Malay Archipelago, but Sir Joseph Hooker considered that its distribution as an indigenous plant probably did not extend to the Malay peninsula. He thought that Durio malaccensis, Planch., which grows in Malacca and Burma, might be the wild form of the durian.
The region in which the tree is commonly found extends from the northern Federated Malay States through the Dutch East Indies and up into the Philippines as far as Mindanao. A single tree is known to have fruited in Hawaii, and another in Dominica, British West Indies. The species is seen occasionally in Ceylon and other tropical countries, but outside of the Malayan region its cultivation is limited mainly to botanic gardens.
The name durian (or dorian) is the only one by which this fruit is known to Europeans. Yule and Burnell say : "Malay duren, Molucca form durivan, from duri, a thorn or prickle (and an, the common substantival ending; Mr. Skeat gives the standard Malay as duriyan or durian)" Various spellings of the word are found in the early writers.
An analysis made in the Philippines by W. E. Pratt shows the fruit to contain: Total solids 44.5 per cent, ash 1.24, acids 0.1, protein 2.3, invert sugar 4.8, sucrose 7.9, and starch 11.0. In the Philippine Journal of Science, November, 1912, O. W. Barrett writes: "The chemical body which is responsible for the very pronounced odor is probably one of the sulfur compounds with some base perhaps related to that in butyric acid; it is not an oil nor a sugar, not a true starch nor an inulin, but according to Dr. W. E. Pratt it is a substance new to the organic chemist. The pulp contains a compound which, it is believed, is related to erythrodextrin, but seems to exist, if such, in a new form in this fruit."
In its climatic requirements the durian is tropical, probably strictly so. The few experiments made indicate that it will not succeed anywhere on the mainland of the United States. It is limited to regions free from frost, and delights in a deep rich soil and abundant moisture. There are many places in the West Indies and elsewhere in tropical America where it should be quite at home. In the Malayan islands, where it is commonly grown, the tree receives little cultural attention, hence nothing is known regarding pruning, irrigation, or other matters which usually give the northern horticulturists much concern. Propagation is ordinarily by seeds, which do not keep long after they are removed from the fruit. It has been learned that they can be shipped successfully from the eastern to the western tropics if they are packed in a mixture of charcoal and coconut fiber, slightly moistened.
The method of budding practiced by Wester, to which reference has been made, differs very little from shield-budding as applied to the avocado and mango. By means of this method of propagation it will be possible to perpetuate superior seedlings, and the number of years required for the tree to come into bearing should be lessened. Wester recommends that the budwood be well beyond the tender stage, but not so old that it is brittle. The petioles should be removed some time before the budwood is to be used, and the petiole-scars given time to heal over; if this is not done, decay may attack the buds. The inverted T-incision is preferred.
No horticultural varieties have yet been established, but several seedling races or forms are known to exist. Barrett says: "In passing we should not forget that there are durians and durians; some are said to be without a strong odor, while to our certain knowledge some of the Borneo varieties are not at all objectionable. Borneo has at least six and probably ten varieties; some of these have only one or two seeds and are comparatively small fruits, while others are fully as large as our largest Jolo or Lake Lanao (Mindanao) forms; the pulp of some is nearly white, while that of others is pale salmon or even orange in color."