Pin feather protective peripheral sheath, longitudinal barb ridges, and growth plates. Over time these barb ridges lengthen helically, branch to create barbs and barbules, and fuse to form the rachis or central shaft. Moreover, the barb plate further differentiate into hooklets and cilia, while the marginal and axial plate die to form the intervening space within the feather structure. During moulting, a bird may get careless and begin to chew at its feathers and might accidentally damage a blood feather. To prevent this, it is necessary that the bird is given chewing toys so that it does not chew at its own
Acorus calamus finger and has numerous coarse fibrous roots below it. The exterior is brown and the interior white. Sweet flag is native to India, central Asia, southern Russia and Siberia, and perhaps Eastern Europe. It also grows in China and Japan. It was introduced into Western Europe and North America for medicinal purposes. Habitats include edges of small lakes, ponds and rivers, marshes, swamps, and wetlands. In addition to "sweet flag" and "calamus" other common names include beewort, bitter pepper root, calamus root, flag root, gladdon, myrtle flag, myrtle grass, myrtle root, myrtle sedge, pine root, rat root, sea sedge, sweet