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-/.

Botany, Mycology. any of several structures having a netlike or skirtlike shape, as the membranous overgrowth covering the sori in ferns.

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

Related formsin·du·si·al, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for indusium

Historical Examples of indusium

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
The sorus is circular and is covered with an indusium which is notched or kidney-shaped.
How to Know the Ferns
S. Leonard Bastin
The indusium is orbicular-reniform, and almost always smooth.
Beautiful Ferns
Daniel Cady Eaton

British Dictionary definitions for indusium

indusium

noun plural -sia (-zɪə)

a membranous outgrowth on the undersurface of fern leaves that covers and protects the developing sporangia

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

indusium in Science

indusium

[ĭn-dōō′zē-əm, -zhē-]

Plural indusia

A thin membrane covering the sorus of a fern. The indusium often shrivels away when spores are ready to be dispersed. Also called fruitcover

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.