calyptra


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calyptra

[kə′lip·trə]
(botany)
A membranous cap or hoodlike covering, especially the remains of the archegonium over the capsule of a moss.
Tissue surrounding the archegonium of a liverwort.
Root cap.
References in periodicals archive ?
Aside from the conic operculum and the costa throughout the inner perichaetial bracts; some of the characters were either circumscribed to a narrower morphological span (seta length), restricted to some inner group (oval leaf cells), or discarded as primitive features (mitrate calyptra).
Two emasculated clusters were not pollinated to ensure that the emasculation was done at correct time and also to check the possible incidence of claistogamie (self polination of any flower without calyptra fall).
The capsules are clearly visible in this photo (taken in Michigan, USA), and are dark, round, and lack a calyptra. When they are ripe, the capsule walls slowly contract, increasing the pressure inside until the operculum (spore case lid) is blown off and the spores are ejected.
Often floral debris (such as leftover anthers, sepals and calyptra) can become nearly 100% infected, serving as inoculum for infections later in the season.
and E-class MADS-Box homologues in Eupoma-tia (Eupomatiaceae): support for the bracteate origin of the calyptra. Int.
Calyx lobes ciliate, persistent; corolla sympetalous, cylindrical, the lobes either fused to form a calyptra that splits transversely and falls at anthesis to leave a persistent basal ring, or lobes free and the corolla tube sometimes constricted at the throat.