Rachis Rachis Rachis is a biological term for a main axis or "shaft" (from the Greek "ράχις, backbone, spine"). In vertebrates a "rachis" can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the "rachis" usually forms the supporting axis of the body and is then called the spine or vertebral column. "Rachis" can also mean the central shaft of pennaceous feathers. In the gonad of the invertebrate nematode "C. elegans", a "rachis" is the central cell-free core or axis of the gonadal arm of both adult males and hermaphrodites where the germ cells have
Acorus calamus β-asarone is 2,4,5-trimethoxycinnamic acid, a derivative which is not a carcinogen. Acorus calamus Acorus calamus (also called sweet flag or calamus, among many common names) is a species of flowering plant, a tall wetland monocot of the family Acoraceae, in the genus "Acorus". Sweet flag is a herbaceous perennial, tall. In habit it resembles the iris, and has given its name to the flag iris, "I. pseudacorus". It consists of tufts of basal leaves that rise from a spreading rhizome. The leaves are erect yellowish-green, radical, with pink sheathing at their bases, sword-shaped, flat and narrow, tapering into a long,