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Related to involucre: raceme, pappus


, pl.


(in'vō-lū'krŭm, -loo'kră),
1. An enveloping membrane, for example, a sheath or sac.
2. The sheath of new bone that forms around a sequestrum.
Synonym(s): involucre
[L. a wrapper, fr. in-volvo, to roll up]


, involucrum (ĭn′vō-lū″kĕr) (ĭn″vō-lū′krŭm) [″ + volvere, to wrap]
1. A sheath or covering.
2. The covering of newly formed bone enveloping the sequestrum in infection of the bone.


  1. a calyx-like structure formed by bracts below the base of a condensed INFLORESCENCE.
  2. a growth of the tissue of the thallus in liverworts (see HEPATICA that covers and protects the ARCHEGONIUM.
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References in periodicals archive ?
Capitulescences monocephalous or lateral and cymose of three to seven heads; capitula short-pedunculate, homogamous, bilabiate, two- to six-flowered; receptacle epaleate; involucre multiseriate, cylindrical, phyllaries woolly.
Capitulescences monocephalous or corymbose; capitula pedunculate, homogamous or heterogamous, radiate; receptacle epaleate; involucre three- to six-seriate.
Capitulescences corymbose; capitula pedunculate, homogamous, ligulate; receptacle epaleate; involucre multiseriate.
Capitulescences monocephalous, terminal; capitula sessile to pedunculate, homogamous or heterogamous, discoid, disciform, or radiate; receptacle epaleate; involucre multiseriate, phyllaries acute at the apex or with an apical, showy appendage.
Capitulescences monocephalous or paniculate to corymbose, terminal; capitula pedunculate, homogamous or heterogamous, radiate; receptacle epaleate, setose; involucre multiseriate.
Capitulescences spicate to paniculate; capitula sessile, homogamous, ligulate, one- to ten-flowered; receptacle epaleate, glabrous to setose; involucre multiseriate.
Capitulescences monocephalous, or corymbose to paniculate; capitula pedunculate, homogamous, discoid or radiate; involucre one- to five-seriate; receptacle epaleate to paleate, paleae embracing the marginal florets, with the open part facing either the center of the capitulum or the outer part of the capitulum.
Capitulescences monocephalous, terminal; capitula short-pedunculate, homogamous, discoid; receptacle epaleate; involucre multiseriate.
Capitulescences racemose to paniculate; capitula unisexual, subsessile to pedunculate; receptacle epaleate; involucre multiseriate, outermost phyllaries often extending into the stalk.
Capitulescences monocephalous or in cymes, terminal; capitula short-petiolate, homogamous, discoid; receptacle epaleate, alveolate; involucre multiseriate.
In the Betulaceae (birches, alders, and relatives), fruits vary from small, winged nutlets in some Alnus and Betula, to medium-sized nutlets with a leafy involucre in Carpinus and Ostrya, to large nuts in Corylus (Stone, 1973; Crane, 1989).
Leptothrips fasciculatus larvae live inside tubular, 3 mm-long flowers and 3-4 mm-deep involucres that surround flower clusters (Wiesenborn 2012).