Rachis
In
is a main axis or "shaft".In zoology and microbiology
In
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 Caenorhabditis 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 achieved pachytene and are attached to the walls of the gonadal tube. The rachis is filled with cytoplasm.[2]
In botany
In
Abies
seed cone disintegrates is also called the rachis.
A ripe head of wild-type wheat is easily
archaeologists as a "brittle rachis", one type of shattering in crop plants.[citation needed
]
-
Fern rachis with alternating 'pinnae', rachillae with attached leaflets -
Inflorescence of Buddleja paniculata
See also
References
- ^ Henry George Liddell, Robert Scott, A Greek–English Lexicon, ράχις
- ISBN 978-1-4614-4015-4. Retrieved 6 August 2013.