Classified as a hardwood tree, the rubberwood (Hevea brasiliensis) belongs to the latex-producing tree family Euphorbiaceae. In the genus of Hevea, 11 species exist but only three species within the genus produce usable rubber: Hevea benthamiana, Hevea brasiliensis and Hevea guianensis. Of the three species, only the rubberwood is grown commercially on plantations for the harvest of rubber and wood.
The seeds of the rubber tree began to be exported from its native home of Brazil in 1876 by a rubber tree planter in the area, Henry Wickham. The seeds were widely imported to London, where they were successfully germinated at the Tropical Herbarium in Kew Gardens. The young trees were exported to Sri Lanka. In Singapore, the art of tapping the tree for its valuable latex was developed.
The rubberwood tree species of the Euphorbiaceae family grows up to 130 feet in height. Capable of self-fertilization, the tree produces abundant yellow flowers that are both male and female. Numerous cultivars have been established to utilize even higher yields of latex from the valuable tree. The tree grows best in tropical lowland regions that are humid.
World Commercial Production
Even though the rubberwood tree species is native to Brazil, it is no longer commercially grown on a large scale in the region due to the South American leaf blight (Microcyclus ulei), which ravaged the trees. The majority of rubberwood trees are now grown in Southeast Asia and parts of Africa. The tree is normally grown on plantations for 20 years while it produces latex and then it is cut down for timber. A valuable lumber tree, the wood it produces is harder than the northern red oak, according to University Loft.
The rubberwood species and all species within the family Euphorbiaceae offer excellent sustainability. An oak tree takes over 60 years before it attains a harvestable size to be used in wood products, but the rubberwood tree can produce three generations of trees within that time span that are harvestable and ready for timber production.
The Euphorbiaceae family stands apart from other plant families because all members within the group produce some form of milky sap. In the case of the rubber tree the milky sap is latex. The family is made is made up of predominantly monoecious (self-fertile) members. The Euphorbiaceae family includes 300 genera and 7,500 species, according to the University of Oklahoma. Such distinctive plants as the holiday poinsettia belong to the Euphorbiaceae family. Among such a wide array of plant life, the rubberwood tree stands apart for its worldwide commercial value in latex and hardwood timber.
The milky latex sap of the Euphorbiaceae family is normally toxic and produces an allergic skin reaction. The toxin within the sap is known as diterpene esters. It can cause severe blistering of the skin. The sap is often manufactured into a topical ointment that is used to battle skin cancer. The sap of the rubberwood tree does not contain the toxin nor does it have any anti-cancer properties.