field scabious vs scabiosa

field scabious and scabiosa both are nouns.

Word	Noun	Adjective	Verb	Adverb
field scabious	Yes	No	No	No
scabiosa	Yes	No	No	No

As nouns, scabiosa is a hypernym of field scabious; that is, scabiosa is a word with a broader meaning than field scabious:

field scabious: perennial having bluish-lilac flowers; introduced in the eastern United States
scabiosa: any of various plants of the genus Scabiosa

Other hypernyms of field scabious include scabious.

field scabious (noun)	scabiosa (noun)
perennial having bluish-lilac flowers; introduced in the eastern United States	any of various plants of the genus Scabiosa