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1. The protective cap or hood covering the spore case of a moss or related plant.
2. A similar hoodlike or caplike structure, such as a root cap.

[Medieval Latin, from Greek kaluptra, veil, from kaluptein, to cover; see kel- in Indo-European roots.]

ca·lyp′trate′ (-trāt′) adj.


1. (Botany) a membranous hood covering the spore-bearing capsule of mosses and liverworts
2. (Botany) any hoodlike structure, such as a root cap
[C18: from New Latin, from Greek kaluptra hood, from kaluptein to cover]
calyptrate adj


(kəˈlɪp trə)

n., pl. -tras.
1. a hood or hoodlike part, as the lid of the capsule in mosses.
2. a root cap.
[1745–55; < New Latin < Greek kalýptra veil, covering]
ca•lyp′trate (-treɪt) adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.calyptra - the hood or cap covering the calyx of certain plants: e.g., the California poppycalyptra - the hood or cap covering the calyx of certain plants: e.g., the California poppy
plant part, plant structure - any part of a plant or fungus
References in periodicals archive ?
The fact that the stigmata were receptive and the opening of anthers occurred before the calyptra fall shows cleistogamy, a form of self-pollination reported in other species (MULLINS et al.
calyptra In mosses, a thin membrane protecting the developing sporophyte and forming a hood over the sporangium (structure containing spores).
the only genus of subfamily Marcgravioideae, but Marcgraviastrum differs from this genus in having 5-merous flowers (4-merous in Marcgravia), petals free or variously connate (completely connate into a calyptra in Marcgravia), and leaves spirally arranged (distichous in Marcgravia).