falls vs floral envelope

falls and floral envelope both are nouns.

Word	Noun	Adjective	Verb	Adverb
falls	Yes	No	No	No
floral envelope	Yes	No	No	No

As nouns, floral envelope is a hypernym of falls; that is, floral envelope is a word with a broader meaning than falls:

falls: the petals or sepals of a flower that bend downward (especially the outer perianth of an iris)
floral envelope: collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils

Other hypernyms of falls include chlamys, perianth, perigone, perigonium.

falls (noun)	floral envelope (noun)
a steep descent of the water of a river	collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils
the petals or sepals of a flower that bend downward (especially the outer perianth of an iris)