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
Calamus rotang Calamus rotang Calamus rotang is a plant species native to India, Sri Lanka and Myanmar (Burma). It one of the scandent (climbing) rattan palms used to make Malacca cane furniture, baskets, walking-sticks, umbrellas, tables and general wickerwork, and is found in Southwest Asia. The basal section of the plant grows vertically for 10 metres or so, after which the slender, tough stem of a few centimetres in diameter, grows horizontally for 200 metres or more. It is extremely flexible and uniform in thickness, and frequently has sheaths and petioles armed with backward-facing spines which enable it to scramble over other