[ in-doo-zee-uhm, -zhee-uhm, -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.

    • an enveloping layer or membrane.

    • 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

Other words from indusium

  • in·du·si·al, adjective

Words Nearby indusium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use indusium in a sentence

  • The indusium is thin and delicate, composed of sinuous-margined cellules, and is more or less wavy along the free edge.

    Beautiful Ferns | Daniel Cady Eaton
  • They are covered by a very slight indusium, which soon falls off.

    How to Know the Ferns | S. Leonard Bastin
  • The indusium arises from a vein to which the sorus is attached.

    How to Know the Ferns | S. Leonard Bastin
  • Thus it is proper to describe the shape of the indusium as peltate.

    How to Know the Ferns | S. Leonard Bastin
  • The sori are narrow, and when young are covered with an indusium.

    How to Know the Ferns | S. Leonard Bastin

British Dictionary definitions for indusium


/ (ɪnˈdjuːzɪəm) /

nounplural -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

Origin of indusium

C18: New Latin, from Latin: tunic, from induere to put on

Derived forms of indusium

  • indusial, adjective

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

Scientific definitions for 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.