Involucre

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Related to involucral: bracteole

involucre

[′in·və‚lü·kər]
(botany)
Bracts forming one or more whorls at the base of an inflorescence or fruit in certain plants.

Involucre

 

the small, tightly packed apical leaves that surround an inflorescence. In plants of the families Compositae and Dipsacaceae, the involucre closely surrounds the inflorescence; as a result, the involucre and the inflorescence appear to form a single flower. In plants of the family Umbelliferae, the involucre is located at the base of the inflorescences, or compound umbels. The leaves at the base of a simple umbel form an involucel. The morphological characteristics of involucres and involucels are used in the taxonomy of the various families.

References in periodicals archive ?
cardunculus showed the presence of triterpenoid saponins in the involucral bracts of this plant (Mucaji et al.
Also, involucral bract shape and width are diagnostic for the parental species (Heiser 1947) and are inherited additively in hybrids (LHR, pers.
About the time resin secretion by floral bractlets became associated with reward rather than defense functions, the involucral bracts evolved larger size and often bright colors, apparently as a floral advertisement to pollinators [ILLUSTRATION FOR FIGURE 3 OMITTED].
The involucral bract and bracteoles of the staminate flower have a single-layered epidermis on both surfaces (see Figure 2A, B).
Involucral bracts linear-lanceolate, acute, [+ or -] 1 mm wide; with stellate, glandular and long simple eglandular trichomes in more or less similar proportions (generally, the eglandular trichomes are the most abundant).
30-55 cm long), involucral bracts and primary bracts green or sometimes reddish at their distal portion (vs.
Euphorbia spellenbergiana is a delicate completely prostrate annual, with entire, oblong to suborbicular, or ovate leaves, reduced subequal or nonexistant involucral gland appendages, smooth (non-ridged) seeds, and puberulent stems.
5 mm de largo, glabras o pilosas, receptaculo conico, paleas exteriores ovadas, ciliadas, ubicadas por pares y rodeando en conjunto con una bractea involucral al aquenio contiguo, las interiores lanceoladas, enteras a someramente trifidas; flores liguladas 5, sus tubos de 1 a 1.
Nature of proximal involucral bract: 0, stipuliform; 1, involucral.
15 mm in diameter, white, glabrous; scape bracts obovate, distinctly concave and inflated toward the apex, apex rounded to obtuse and apiculate, erect, entire, whitish-hyaline in the basal 3/5, red in the apical 2/5, inconspicuously and sparsely white-lepidote inside, glabrous outside, membranous, the upper ones somewhat involucral, 35-45 x 25 mm, about equaling 2/5 of the sepals length.
Within the inflorescence, branches are usually subtended by primary or involucral bracts (Goetghebeur, 1986).
It differs from most Mexican Scirpeae in having well developed leaves and foliaceous involucral bracts, characters shared with Bolboschoenus and Scirpus sensu stricto.