Tree pine ("Pinus" species) the bark exudes sticky resin which deters attackers whereas in rubber trees ("Hevea brasiliensis") it is a milky latex that oozes out. The quinine bark tree ("Cinchona officinalis") contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta, Arecales, Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings. Although the bark functions as a protective barrier, it is itself attacked by boring insects such as beetles. These lay their eggs in crevices and the larvae chew their way through the cellulose
Cinchona prefer the pronunciation for the common name of the plant. The national tree of Peru is in the genus "Cinchona". "Cinchona" plants belong to the family Rubiaceae and are large shrubs or small trees with evergreen foliage, growing in height. The leaves are opposite, rounded to lanceolate and 10–40 cm long. The flowers are white, pink or red, produced in terminal panicles. The fruit is a small capsule containing numerous seeds. A key character of the genus is that the flowers have marginally hairy corolla lobes. The tribe Cinchoneae includes other genera "Cinchonopsis", "Jossia", "Ladenbergia", "Remijia", "Stilpnophyllum", and "Ciliosemina". In