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
Quercus leucotrichophora to October. Naturally, it regenerates via seeds. "Quercus leucotrichophora" is distributed in Northern India, Nepal, Myanmar, Pakistan, and Sri Lanka. In Nepal, it naturally occurs at 1500–2700 m in forested areas in association with "Rhododendron arboreum". In the Himalayas, "Quercus leucotrichophora" is lopped for fodder from December to June. Its wood is used in building purposes and as a good fuel. The acorns are edible, and the seeds can be roasted to make a coffee substitute. "Quercus leucotrichophora" also has uses in ethnomedicine, the gum being used for treating colds and as an analgesic. The tree is affected with many