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 officinalis of malaria. Other alkaloids that are extracted from this tree include cinchonine, cinchonidine and quinidine. Cinchona officinalis Cinchona officinalis is a South American tree in the Rubiaceae family. It is native to wet montane forests in Colombia, Ecuador, Peru and Bolivia, between 1600–2700 meters above sea level. Cinchona officinalis is a shrub or tree with rugose bark and branchlets covered in minute hairs. Stipules lanceolate or oblong, acute or obtuse, glabrous. Leaves lanceolate to elliptic or ovate, usually about 10 cm. long and 3.5–4 cm. wide; acute, acuminate, or obtuse tip; base rounded to attenuate; coriaceous, glabrous above and often