rachis
Americannoun
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Botany.
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the axis of an inflorescence when somewhat elongated, as in a raceme.
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(in a pinnately compound leaf or frond) the prolongation of the petiole along which the leaflets are disposed.
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any of various axial structures.
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Ornithology. the part of the shaft of a feather bearing the web.
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Anatomy. spinal column.
noun
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botany the main axis or stem of an inflorescence or compound leaf
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ornithol the shaft of a feather, esp the part that carries the barbs
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another name for spinal column
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of rachis
1775–85; < New Latin < Greek rháchis spine, ridge, backbone
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Each leaflet may have its own stalk, but is attached to the rachis.
From Textbooks ● Jun. 9, 2022
“The thickness of the rachis in some specimens is 3 microns thick. That’s less than the size of the average cell,” O’Connor says.
From Science Magazine ● Dec. 14, 2018
That combination of features—weak rachis and evenly-spaced barbules—has not previously been directly observable in the flattened 2-dimensional fossils, Holtz says.
From Science Magazine ● Dec. 8, 2016
But this specimen lacked the rachis; it just had barbs and barbules down its ribbonlike tail.
From New York Times ● Dec. 8, 2016
It had a magenta rachis down the center with soft green vanes that shimmered yellow and purple and blue depending on how you turned it.
From "The Reader" by Traci Chee
Sometimes at the base of the rachises, main or secondary, glandular streaks are seen as in the rachises of Sporobolus coromandelianus.
From A Handbook of Some South Indian Grasses by Rangachari, K.
Many species of Andropogon have such jointed rachises.
From A Handbook of Some South Indian Grasses by Rangachari, K.
The inflorescence is a spike-like panicle, with very short filiform inarticulate branches and rachises.
From A Handbook of Some South Indian Grasses by Rangachari, K.
The female inflorescence is a large globose head consisting of short spikelets articulate at the very base of the rachis, short bracts and very long, spreading, rigid rod-like rachises.
From A Handbook of Some South Indian Grasses by Rangachari, K.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
