Medicago sativa vs lucerne

Medicago sativa and lucerne both are nouns.

Word	Noun	Adjective	Verb	Adverb
Medicago sativa	Yes	No	No	No
lucerne	Yes	No	No	No

As nouns, Medicago sativa and lucerne are synonyms defined as:

Medicago sativa and lucerne: important European leguminous forage plant with trifoliate leaves and blue-violet flowers grown widely as a pasture and hay crop

Other synonyms of Medicago sativa include alfalfa.

Medicago sativa (noun)	lucerne (noun)
important European leguminous forage plant with trifoliate leaves and blue-violet flowers grown widely as a pasture and hay crop	important European leguminous forage plant with trifoliate leaves and blue-violet flowers grown widely as a pasture and hay crop