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 (rā′fīd) also ra·phis (-fĭs)
n. pl. raph·i·des (răf′ĭ-dēz′) or ra··phis·es
One of a bundle of needlelike crystals of calcium oxalate occurring in many plant cells.

[French, sing. of raphides, from New Latin, from Greek rhaphides, pl. of rhaphis, needle, from rhaptein, to sew; see wer- in Indo-European roots.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˈreɪfaɪd) or


n, pl raphides (ˈræfɪˌdiːz)
(Biochemistry) any of numerous needle-shaped crystals, usually of calcium oxalate, that occur in many plant cells as a metabolic product
[C18: from French, from Greek rhaphis needle]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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References in periodicals archive ?
Of the CaOx crystals in plants, five forms have been recognised (Franceschi and Homer 1980)--crystal sand, raphide, druse, styloid and prismatic.
Prostratin, colorless raphide, was prepared from the roots of Euphorbia fischeriana which were collected in Heilongjiang Province, China and the voucher specimen (No.
Elongate, multicellular raphide sacs form parallel rows in all organs investigated.
Artefact Starch Raphide 'Cooked' Charred number granule size lengths starch interior range ([micro]m) ([micro] m) granules on residue interior 47 1-5 20-30 [check] 56 1-4 10-20 [check] [check] 58 1-5 20-30 59 1-5 10-30 60 1-5 10-20 84 1-4 10-20 [check] [check] 95 1-4 20-31 * 96 1-5 25-50 [check] [check] 99 1-6 14-28 [check] * 2.4 1-4 15-35 [check] 2.5 1-5 10-45 [check] 2.6 1-5 10-20 2.7 1-5 15-35 2.8 1-4 20-45 2.9 1-5 15-32 [check] * 2.10 1-5 20-40 2.11 1-6 22-45 2.13 1-4 10-30 [check] 2.14 1-5 10-20 2.15 1-5 20-30 [check] * * Denotes ambiguous residue.
The identification is based on starch grain and xylem vessel morphology, and raphide concentration.
Among all crystal types, raphide bundles and their enclosing cells present the largest variation in this or any other family and have been subject to more intensive study (Keating, in press a).
The fruits resemble Indian Maize and develop in a sheath; as they ripen they exude an aroma of Jackfruit but because the sheath contains Calcium Oxalates in the form of needle-like crystals (Raphides) that will lodge in the throat and gums.
Although the precise toxicity mechanism is unknown, calcium oxalate crystals (raphides) and protease in the idioblast of the plant are considered to be the causes.
(ST = stomata; SC = substomatal chamber; M = mesophyll; AdE = adaxial epidermis; AbE = abaxial epidermis; X = xylem; P = phloem; BPF = bundle of phloematic fibers; BXF = bundle of xylem fibers; Hi = hipodermis; R = raphides; OC = ornamented cuticle).
In terms of microscopic identification, Dendrobium officinale could be identified by vascular bundle sheath observed under the fluorescence microscopy and the distribution of raphides under normal light microscopy [95].