Plant stem stems are asparagus, bamboo shoots, cactus pads or nopalitos, kohlrabi, and water chestnut. The spice, cinnamon is bark from a tree trunk. Gum arabic is an important food additive obtained from the trunks of "Acacia senegal" trees. Chicle, the main ingredient in chewing gum, is obtained from trunks of the chicle tree. Medicines obtained from stems include quinine from the bark of cinchona trees, camphor distilled from wood of a tree in the same genus that provides cinnamon, and the muscle relaxant curare from the bark of tropical vines. Wood is used in thousands of ways, e.g. buildings, furniture, boats,
Cinchona la Quina" (1793) with illustrations. He proposed a Spanish expedition to search for plants of commercial value which was approved in 1783 and was continued after his death in 1808 by his nephew Sinforoso Mutis. As demand for the bark increased the trees in the forests began to be destroyed. To maintain their monopoly on cinchona bark, Peru and surrounding countries began outlawing the export of cinchona seeds and saplings beginning in the early 19th century. The Colonial European powers considered growing the plant in other tropical parts. The French mission of 1743, of which de la Condamine was member,