calyx tube vs floral cup

calyx tube and floral cup both are nouns.

Word	Noun	Adjective	Verb	Adverb
calyx tube	Yes	No	No	No
floral cup	Yes	No	No	No

As nouns, calyx tube and floral cup are synonyms defined as:

calyx tube and floral cup: the cuplike or ringlike or tubular structure of a flower which bears the sepals and stamens and calyx (as in Rosaceae)

Other synonyms of calyx tube include hypanthium.

calyx tube (noun)	floral cup (noun)
the cuplike or ringlike or tubular structure of a flower which bears the sepals and stamens and calyx (as in Rosaceae)	the cuplike or ringlike or tubular structure of a flower which bears the sepals and stamens and calyx (as in Rosaceae)