rachis

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Related to rachides: rachilla

ra·chis

 (rā′kĭs)
n. pl. ra·chis·es or rach·i·des (răk′ĭ-dēz′, rā′kĭ-)
1.
a. The main stem of an elongated inflorescence, as in a grass.
b. The main axis of a pinnately compound leaf or of a fern frond.
2. The main shaft of a bird's feather, especially the part to which the barbs are attached.
3. The spinal column.

[New Latin, from Greek rhakhis, spine, ridge.]

ra′chi·al adj.

rachis

(ˈreɪkɪs) or

rhachis

n, pl rachises, rhachises, rachides or rhachides (ˈrækɪˌdiːz; ˈreɪ-)
1. (Botany) botany the main axis or stem of an inflorescence or compound leaf
2. (Zoology) ornithol the shaft of a feather, esp the part that carries the barbs
3. (Anatomy) another name for spinal column
[C17: via New Latin from Greek rhakhis ridge]
rachial, rhachial rachidial, rhachidial adj

ra•chis

(ˈreɪ kɪs)

n., pl. ra•chis•es, rach•i•des (ˈræk ɪˌdiz, ˈreɪ kɪ-)
1. any of various axial structures of a plant, as the stem of a leaflet.
2. the part of the shaft of a feather bearing the web.
[1775–85; < New Latin < Greek rháchis spine]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.rachis - axis of a compound leaf or compound inflorescencerachis - axis of a compound leaf or compound inflorescence
axis - the main stem or central part about which plant organs or plant parts such as branches are arranged
2.rachis - the series of vertebrae forming the axis of the skeleton and protecting the spinal cordrachis - the series of vertebrae forming the axis of the skeleton and protecting the spinal cord; "the fall broke his back"
notochord - a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
chine - backbone of an animal
canalis vertebralis, spinal canal, vertebral canal - the canal in successive vertebrae through which the spinal cord passes
coccyx, tail bone - the end of the vertebral column in humans and tailless apes
vertebra - one of the bony segments of the spinal column
intervertebral disc, intervertebral disk - a fibrocartilaginous disc serving as a cushion between all of the vertebrae of the spinal column (except between the first two)
skeletal structure - any structure created by the skeleton of an organism
axial skeleton - the part of the skeleton that includes the skull and spinal column and sternum and ribs
Translations

ra·chis

n. raquis, la columna vertebral.
References in periodicals archive ?
from rachides of dead leaves of Acoelorrhaphe wrightii collected in southeastern Florida.
Both characters 43 and 44 are extensions of the morphological diversity displayed by the vascular tissues of frond rachides and are encompassed by character 24 of Pryer et al.
Precision degaging was done under a stereomicroscope to probe primary rachides for secondary-pinna attachment, ultimate rachides for foliar attachment, and to expose ramifications of asymmetrical branching (e.