Let’s know about Rachis
In zoology and microbiology
In vertebrates, 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 achieved pachytene and are attached to the walls of the gonadal tube. The rachis is filled with cytoplasm.
In plants, a rachis is the main axis of a compound structure. It can be the main stem of a compound leaf, such as in Acacia or ferns, or the main, flower-bearing portion of an inflorescence above a supporting peduncle. Where it subdivides into further branches, these are known as rachilla (plural rachillae).
A ripe head of wild-type wheat is easily shattered into dispersal units when touched or blown by the wind. A series of abscission layers forms that divides the rachis into dispersal units consisting of a small group of flowers (a single spikelet) attached to a short segment of the rachis. This is significant in the history of agriculture, and referred to by archaeologists as a “brittle rachis”, one type of shattering in crop plants.
What is the meaning of inflorescence?
The inflorescence can also be defined as the reproductive part of a plant that bears a distinctive appearance in an arbor. The entire inflorescence is called a stalk and the principal stem (incorrectly referred to as the main stem) holds the spindle.
How many types of inflorescences are there?
Flower is the reproductive unit of angiosperms. The arrangement of flowers on the floral axis is called an inflorescence. The main axis of the inflorescence is known as the stem. Mainly there are two types of inflorescences- Asimakshi and Sasimakshi.
What is the type of inflorescence in hibiscus?
Cecalis: It is the outermost circle of the flower, it is usually green in color and protects the flower in the bud stage, they are of two types. (a) Combined sepals: When sepals are joined together, e.g. hibiscus, datura etc. (b) Separate sepals: When the sepals are separate, for example – brinjal, tomato, chilli etc.
Explain what is a flower?
A flower, or flower, is the reproductive structure found in plants. They are found in plants of the Magnoliophyta type, also called agnio spermatozoa. The biological function of a flower is to mediate the union of the male sperm and the female spore.