bract vs involucre

bract and involucre both are nouns.

Word	Noun	Adjective	Verb	Adverb
bract	Yes	No	No	No
involucre	Yes	No	No	No

As nouns, involucre is a hyponym of bract; that is, involucre is a word with a more specific, narrower meaning than bract:

bract: a modified leaf or leaflike part just below and protecting an inflorescence
involucre: a highly conspicuous bract or bract pair or ring of bracts at the base of an inflorescence

Other hyponyms of bract include calycle, calyculus, epicalyx, false calyx, bracteole, bractlet, spathe, glume.

bract (noun)	involucre (noun)
a modified leaf or leaflike part just below and protecting an inflorescence	a highly conspicuous bract or bract pair or ring of bracts at the base of an inflorescence