rachis

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Related to rachises: rachial

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 ?
Kathleen lnman, who owns a small winery and an eight-acre vineyard in Sonoma's Russian River Valley, prefers to use entire bunches during the fermentation process; she says the rachises "act like a cage to protect some of the berries" and lend flavor and texture.
The association of Alternaria with clusters displaying symptoms of red rachises suggests that more research needs to be done that focuses on why these saprophytic and opportunistic pathogens are not being controlled with current pest-management programs.
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.
Another factor that affects the visual aspect of the lawn is the intense emergence of flower rachises, especially in lawns formed by P notatum in which the color of the inflorescence is different from the color of the leaves.
Variety Sultan was high in CAT activity with respect to grain and rachises while the Golden in corn silk.
When multiple rachises and fruit with sugar accumulation disorder were tested for minerals, the only consistent difference from normally developing fruit or rachises was increased calcium in the rachis tissue (Krasnow et al.
Rachises are scaly, papillate, with occasional aerophores in the base of pinnae.
Pistillate inflorescences are smaller and more contracted than staminate ones, and the rachises are very compact and covered by 30-50 flowers.
Two specimens correspond to nearly complete fronds showing a primary rachis bifurcating, at an angle of about 30[degrees], into two pinnae rachises 20 to 26 cm long.