indusium

[ in-doo-zee-uhm, -zhee-uhm, -dyoo- ]

noun

, plural in·du·si·a [in-, doo, -zee-, uh, -zhee-, uh, -, dyoo, -].

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.

indusium

/ ɪnˈdjuːzɪəm /

noun

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

indusium

/ ĭn-do̅o̅′zē-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.
2. Also called fruitcover
3. 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.

Derived Forms

• inˈdusial, adjective

Other Words From

• in·dusi·al adjective

Word History and Origins

Origin of indusium¹

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

Word History and Origins

Origin of indusium¹

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

Example Sentences

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

From Project Gutenberg

They are covered by a very slight indusium, which soon falls off.

From Project Gutenberg

The indusium arises from a vein to which the sorus is attached.

From Project Gutenberg

Thus it is proper to describe the shape of the indusium as peltate.

From Project Gutenberg

The sori are narrow, and when young are covered with an indusium.

From Project Gutenberg