Definition of involucre in English:

involucre

(also involucrum)

noun

Botany
  • A whorl or rosette of bracts surrounding an inflorescence (especially a capitulum) or at the base of an umbel.

    • ‘The Hermaphrodite cyathium shows the characteristics measured (length and width of the cyathium involucre and the nectary).’
    • ‘All flowers are enclosed within an involucre with four marginal glands.’
    • ‘Basal leaves and flowers initiate from a tuberous rhizome and three green cauline leaves arranged in a whorl form an involucre around the developing flower.’
    • ‘We used to help my grandmother gather the flowers, remove the green involucre from beneath the flowerhead and separate the rays, or florets.’
    • ‘The cupules are simple involucres of bracts which are spirally arranged (according to a Fibonacci pattern) on the floral axis preceding the flower.’

Origin

Late 16th century: from French, or from Latin involucrum, from involvere roll in, envelop (see involve).

Pronunciation:

involucre

/ˈinvəˌlo͞okər/