Rubber Tree | OtterKnow Kids Encyclopedia

What Is the Rubber Tree?

The rubber tree, known scientifically as Hevea brasiliensis, is the source of natural rubber used in thousands of products around the world. Originally from the Amazon rainforest in South America, this tropical tree can grow up to 100 feet tall in the wild. The tree produces a milky white liquid called latex, which flows through special tubes in the bark like sap flows through a maple tree. Indigenous peoples of the Amazon had been using this sticky substance for centuries before Europeans first encountered it. Today, rubber trees are grown on vast plantations across Southeast Asia, which produces about 90 percent of the world’s natural rubber.

Tapping for Latex

Harvesting latex from a rubber tree is a careful, skilled process called tapping. Workers make a thin, angled cut in the bark of the tree, just deep enough to reach the latex vessels without damaging the wood underneath. The milky latex slowly drips from the cut into a small cup attached to the trunk, much like collecting sap from a maple tree. A single tree produces about one-third of a cup of latex per day, and it can be tapped every other day for most of the year. The bark grows back over the cut within a few days, and a well-managed rubber tree can be tapped for 25 to 30 years.

The Vulcanization Breakthrough

For centuries, natural rubber had a frustrating problem: it became sticky and soft in hot weather and hard and brittle in the cold. In 1839, an American inventor named Charles Goodyear accidentally discovered a process called vulcanization that solved this problem. Goodyear found that mixing rubber with sulfur and heating it created a material that stayed flexible in any temperature. This discovery transformed rubber from a curiosity into one of the most important industrial materials in history. Vulcanized rubber could be made into tires, hoses, gaskets, shoe soles, and hundreds of other useful products.

The Great Rubber Smuggling

The story of how rubber plantations spread around the world reads like an adventure novel. In the 1870s, Brazil held a virtual monopoly on rubber because all the world’s rubber trees grew wild in the Amazon. In 1876, a British explorer named Henry Wickham collected about 70,000 rubber tree seeds and shipped them to England, where they were planted at the Royal Botanic Gardens at Kew. Seedlings from these trees were then sent to British colonies in Sri Lanka and Malaysia, where they thrived on large plantations. Within a few decades, Southeast Asian plantations were producing so much rubber that Brazil’s rubber boom collapsed entirely.

Rubber in Our Lives

Natural rubber is found in an astonishing number of everyday products that most people never think about. About 70 percent of all natural rubber goes into making tires for cars, trucks, airplanes, and bicycles. Rubber is also used in medical gloves, elastic bands, erasers, waterproof boots, and the soles of sneakers. While synthetic rubber made from petroleum can substitute for natural rubber in many uses, some products like aircraft tires and surgical gloves require the real thing. Scientists are even exploring other plants, like the Russian dandelion and the guayule shrub, as alternative sources of natural rubber to reduce our dependence on a single species.