peristome
Americannoun
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Botany. the one or two circles of small, pointed, toothlike appendages around the orifice of a capsule or urn of mosses, appearing when the lid is removed.
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Zoology. any of various structures or sets of parts that surround or form the walls of a mouth or mouthlike opening.
noun
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a fringe of pointed teeth surrounding the opening of a moss capsule
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any of various parts surrounding the mouth of invertebrates, such as echinoderms and earthworms, and of protozoans
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A fringe of toothlike appendages surrounding the mouth of the spore capsule of some mosses. The teeth unfold under damp conditions and curl up under dry conditions to disperse spores gradually.
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The area or parts around the mouth in certain invertebrates, such as the echinoderms.
Other Word Forms
Derived Forms
Etymology
Origin of peristome
From the New Latin word peristoma, dating back to 1790–1800. See peri-, -stome
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.
A structure called a peristome increases the spread of spores after the tip of the capsule falls off at dispersal.
From Textbooks • Jan. 1, 2015
When moist the peristome closes hygrometrically over the orifice more or less; when drier the teeth or processes commonly bend outward or recurve; and then the spores more readily escape.
From The Elements of Botany For Beginners and For Schools by Gray, Asa
The mouth and relatively small peristome are situated in the lower third of the body.
From Marine Protozoa from Woods Hole Bulletin of the United States Fish Commission 21:415-468, 1901 by Calkins, Gary N. (Gary Nathan)
Summit of an open spore-case of a Moss, which has a peristome of 16 pairs of teeth.
From The Elements of Botany For Beginners and For Schools by Gray, Asa
Each mesentery is attached by its upper margin to the peristome, by its outer margin to the body-wall, and by its lower margin to the basal disk.
From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 2 "Anjar" to "Apollo" by Various
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.
