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,
History of malaria and make them more susceptible to other diseases. Spanish missionaries found that fever was treated by Amerindians near Loxa (Peru) with powder from Peruvian bark (later established to be from any of several trees of genus "Cinchona"). It was used by the Quechua Indians of Peru to reduce the shaking effects caused by severe chills. Jesuit Brother Agostino Salumbrino (1561–1642), who lived in Lima and was an apothecary by training, observed the Quechua using the bark of the cinchona tree for that purpose. While its effect in treating malaria (and hence malaria-induced shivering) was unrelated to its effect in controlling