indusium

[in-doo-zee-uh m, -zhee-uh m, -dyoo-]
noun, plural in·du·si·a [in-doo-zee-uh, -zhee-uh, -dyoo-] /ɪnˈdu zi ə, -ʒi ə, -ˈdyu-/.
  1. Botany, Mycology. any of several structures having a netlike or skirtlike shape, as the membranous overgrowth covering the sori in ferns.
  2. Anatomy, Zoology.
    1. an enveloping layer or membrane.
    2. a thin layer of gray matter on the corpus callosum.

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
Related formsin·du·si·al, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for indusia

Historical Examples of indusia

  • The indusia are soon thrown off when the spore cases start to develop.

    How to Know the Ferns

    S. Leonard Bastin

  • The sori have indusia, but this is hidden by the margin of the pinnules, which are recurved.

    How to Know the Ferns

    S. Leonard Bastin

  • The sori are quite naked, no indusia being present at any time.

    How to Know the Ferns

    S. Leonard Bastin

  • Like all the Polypodies the clusters of sporangia have no indusia.

    How to Know the Ferns

    S. Leonard Bastin

  • The indusia appear as little whitish scales on the back of the veins.

    Beautiful Ferns

    Daniel Cady Eaton


British Dictionary definitions for indusia

indusium

noun plural -sia (-zɪə)
  1. a membranous outgrowth on the undersurface of fern leaves that covers and protects the developing sporangia
  2. an enveloping membrane, such as the amnion
Derived Formsindusial, adjective

Word Origin for indusium

C18: New Latin, from Latin: tunic, from induere to put on
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

indusia in Science

indusium

[ĭn-dōōzē-əm, -zhē-]
Plural indusia
  1. A thin membrane covering the sorus of a fern. The indusium often shrivels away when spores are ready to be dispersed. Also called fruitcover
  2. 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.