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.

The meaning of RACHIS is an axial structure. an axial structure: such as; the elongated axis of an inflorescence; an extension of the petiole of a compound leaf that bears the leaflets… See the full definition

The main stem of an elongated inflorescence, as in a grass. The principal axis of an inflorescence or of a compound leaf. Spinal column. The shaft of a feather, esp. that part bearing the barbs. (zoology, anatomy) The spine or the vertebrae of the spine. From New Latin, from Ancient Greek ῥάχις (rhakhis, “spine, ridge" ).

Fruit.—Fleshy, coalescent and sunk in the rachis. Rachis definition: . See examples of RACHIS used in a sentence.

3 meanings: 1. botany the main axis or stem of an inflorescence or compound leaf 2. ornithology the shaft of a feather, esp the.... Click for more definitions.

RACHIS definition: 1. the central stem of a leaf or flower spike that has several parts: 2. the spine (= line of…. Learn more.

2025年1月2日 · rachis (plural rachises or rachides) (obsolete, zoology, anatomy) The spinal column, or the vertebrae of the spine. [17th–19th c.] An anatomical shaft or axis in a marine invertebrate. [from 18th c.]

DISCLAIMER: These example sentences appear in various news sources and books to reflect the usage of the word ‘rachis'. Views expressed in the examples do not represent the opinion of …

1. a thornlike process or projection; called also acantha and spina. 2. the rigid bony structure in the midline of the back, composed of the vertebrae; called also backbone, spinal column, and vertebral column. The spinal column is the axis of the skeleton; the skull and limbs are in …

The rachis tapers off toward the top and is grooved longitudinally. It possesses three types of hairs: (i) the fine types spread in the rachel furrows; (ii) the long hairs on the rachel ridges; and (iii) the scarbid hairs on the ridges. The rachis elongates and forms branches and branchlets with a rapid increase in dimensions.