indusium
Americannoun
plural
indusia-
Botany, Mycology. any of several structures having a netlike or skirtlike shape, as the membranous overgrowth covering the sori in ferns.
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Anatomy, Zoology.
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an enveloping layer or membrane.
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a thin layer of gray matter on the corpus callosum.
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noun
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a membranous outgrowth on the undersurface of fern leaves that covers and protects the developing sporangia
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an enveloping membrane, such as the amnion
plural
indusia-
A thin membrane covering the sorus of a fern. The indusium often shrivels away when spores are ready to be dispersed.
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Also called fruitcover
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A cuplike structure fringed with hairs and located at the top of the style in flowers of the family Goodeniaceae (which includes the garden flowers lobelia and scaevola). Pollen is deposited into the indusium by the anthers of the same flower and, as the style grows, carried up for dispersal by pollinating insects.
Other Word Forms
- indusial adjective
Etymology
Origin of indusium
1700–10; < New Latin; Latin: kind of tunic, perhaps < Greek éndys ( is ) dressing, dress ( endý ( ein ) to put on + -sis -sis ) + Latin -ium, for Greek -ion noun suffix
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.
Sori more or less elongated, without indusium, placed on the back of the frond, usually along the veins or near their extremities.
From Project Gutenberg
Wheeler, however, compares with the “dorsal organ” the peculiar extra embryonic membrane or indusium which he has observed between serosa and amnion in the embryo of the grasshopper Xiphidium.
From Project Gutenberg
In Maidenhair-Ferns a little lobe of the leaf is folded back over each fruit-dot, to serve as its shield or indusium.
From Project Gutenberg
When the fruit is ripe, the indusium is something of a lilac colour, spotting the frond in double rows—as you see it there.
From Project Gutenberg
Short, indusium usually more or less curved and frequently crossing a vein.
From Project Gutenberg
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.
