calyptra

[kuh-lip-truh]

noun

Botany.

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

2. a root cap.

calyptra

/ 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

calyptra

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

Other Word Forms

• calyptrate adjective

Word History and Origins

Origin of calyptra¹

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

Word History and Origins

Origin of calyptra¹

C18: from New Latin, from Greek kaluptra hood, from kaluptein to cover

Example Sentences

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

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

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Thallus decumbent, irregularly lobed, 1–2´ long, 3–5´´ wide; involucre none; pedicel ¾–1´ long, sometimes folded upon itself and remaining within the calyptra, the capsule thus appearing sessile; antheridia on elongated receptacles.—Wooded swamps.

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

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

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