Melilotus alba vs melilotus

Melilotus alba and melilotus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Melilotus alba	Yes	No	No	No
melilotus	Yes	No	No	No

As nouns, melilotus is a hypernym of Melilotus alba; that is, melilotus is a word with a broader meaning than Melilotus alba:

Melilotus alba: biennial plant; valuable honey plant
melilotus: erect annual or biennial plant grown extensively especially for hay and soil improvement

Other hypernyms of Melilotus alba include melilot, sweet clover.

Melilotus alba (noun)	melilotus (noun)
biennial plant; valuable honey plant	erect annual or biennial plant grown extensively especially for hay and soil improvement