calyptra

American  

[kuh-lip-truh] / kəˈlɪp trə /

noun

Botany.

1. Also called cap.  a hood or hoodlike part, as the lid of the capsule in mosses.

2. a root cap.

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calyptra British  

/ kəˈlɪptrə, kəˈlɪpˌtreɪt /

noun

1. a membranous hood covering the spore-bearing capsule of mosses and liverworts

2. any hoodlike structure, such as a root cap

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calyptra Scientific  

/ kə-lĭp′trə /

1. In some bryophyte plants, a structure that covers the young sporophyte as it develops within the tissues of its gametophyte parent. The calyptra, which consists of a thickening of the archegonium walls, eventually breaks open as the spore capsule grows.

2. See root cap

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Other Word Forms

• calyptrate adjective

Etymology

Origin of calyptra

1745–55; < New Latin < Greek kalýptra veil, covering, equivalent to kalýp ( tein ) to veil, cover + -tra noun suffix

Example Sentences

The ripped-off piece of its birthplace often remains stuck to the top of the sporophyte and is called a calyptra.

From Scientific American

If not preserved in an envelope the calyptra and operculum are very apt to fall off and become lost.

From Project Gutenberg

Involucral leaves coalescent into an oblong truncate hairy tube, blended in our species with the calyptra; perianth none.

From Project Gutenberg

The calyptra or veil is remarkably small, smooth, and membranous.

From Project Gutenberg

D, capsules of Bartramia: i, with; ii, without the calyptra.

From Project Gutenberg