ˈinvəˌlükə(r) also -vəlˌyü- noun
( -s )
Etymology: French, from New Latin involucrum involucre
: one or more whorls of bracts situated below and close to a flower, flower cluster, or fruit (in a seed plant): as
a. : a rosette of bracts surrounding a composite flower head (as a daisy) and often resembling a true calyx — see cupule 1a
b. : a whorl of bracts subtending the inflorescence in many members of the Umbelliferae