We now come to the tree which until quite recently most people have been accustomed to regard as the indiarubber plant par excellence. In its native home in Assam and Upper Burma, Ficus elastica grows into an enormous tree, which few people would recognise at first sight as the familiar indiarubber plant of suburban front rooms. The adult tree develops huge buttress roots, and the leaves on old branches are only three or four inches in length. The fruits are little greenish-yellow figs, half an inch long. They form one of the principal foods of flying foxes.
In tapping; cuts are made on the aerial roots and even on the horizontal branches at intervals of a few inches. The tree has to be climbed twice, once for tapping, and again a day or two later in order to collect the rubber. The dried rubber is torn away from the cuts and rolled together into a ball. Eight or ten pounds is said to be obtainable from a tree at one tapping.
Ficus elastica also occurs in Java and Sumatra, and both here and in Assam considerable plantations of it have been established. In the Dutch East Indies, however, it is being rapidly ousted by Hevea as a plantation rubber.
Prior to the introduction of Hevea, the best rubber of the Malay peninsula was obtained from species of Willughbeia large woody climbers, with stems six or eight inches in diameter. Other rubber-producing plants occur, but none of these are any longer of much economic importance. Some of the species concerned extend eastward to Siam, Cambodia and Cochin China. Among these another climber, Parameria glanduliferay has been described as one of the most prominent. Species of Willughbeia also occur in Borneo, where they possess some economic importance. In New Guinea rubber is obtained from a species of
Ficus, and in Fiji from Alstonia plutnosa. In all these countries the development of plantations is rapidly supplanting the collection of wild rubber.