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 calyptra buds to form a mature gametophyte.

From Textbooks • Jan. 1, 2015

B, plant with ripe sporogonium. cal. calyptra, × 2.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton

Capsules short-pedicelled, or sessile on the thallus, or immersed in its substance, free or connate with the calyptra, globose, at length rupturing irregularly.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Gray, Asa

The upper portion of the archegonial wall is carried up as a calyptra on the sporogonium, which, as in Sphagnum, has no seta and is raised on a pseudopodium.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various

I, ripe capsules of hairy-cap moss: i, with; ii, without calyptra.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton