rachis


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Related to rachis: petiolule

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 ?
Mesosoma about as wide as head width; mesoscutum 1.5x wider than long, 2.4x longer than mesoscutellum, 4.2x longer than metanotum; propodeum with basal part about 0.9x mesoscutellum length in dorsal view; protibial spur with apical portion of rachis long, about as long as malus, with four elongate branches (not including apical portion of rachis); mesotibial spur straight, with coarse branches, 0.8x mesobasitarsus length; metatibial spurs about the same length, curved apically; pretarsal claws with inner ramus slightly shorter than the outer.
Productive characteristics were: number of bunches, bunch mass, rachis mass, bunch length, number of berries, mass of 50 berries and yield (considering planting density of 2,778 plants [ha.sup.-1]).
As soon as the date for the festival approaches, shops are flooded with rachis of various colours.
A mechanical harvester works by shaking a vine so fast the grapes fall off, leaving behind the rachis stem--the main axis of each cluster--and splitting some of the individual grapes.
Using a precision knife, slice down the rachis (the center shaft) of the ostrich plume, leaving enough room to keep the feather together but cutting off the bulky stiffness of the rachis.
Number of leaflets-NLL, Rachis length-RL, Petiole width-PW, Petiole depth-PD, Leaflet length-LLL and Leaflet width-LLW were measured on 17th leaf.
The fruits were evaluated for physicochemical parameters such as abscission, abscission resistance, skin color, berry firmness, decay incidence, soluble solids, titratable acidity, weight loss, rachis and berry dry matter, and rachis browning.
Pestalotiopsis also has been associated with rachis infections that result in berry shrivel in vinifera vineyards.
australis cannot be entirely attributed to the effects of insect herbivores, however, since significantly more flowers were produced in bison-grazed habitats and floral reproductive allocation was higher even when only rachis masses (rachises were uneaten by Epicauta sp.) were considered.
They made futile attempts with the rachis of the palmyra leaf for pushing the object in to the rumen.