Monarda didyma vs monarda

Monarda didyma and monarda both are nouns.

Word	Noun	Adjective	Verb	Adverb
Monarda didyma	Yes	No	No	No
monarda	Yes	No	No	No

As nouns, monarda is a hypernym of Monarda didyma; that is, monarda is a word with a broader meaning than Monarda didyma:

Monarda didyma: perennial aromatic herb of eastern North America having variously colored tubular flowers in dense showy heads
monarda: any of various aromatic herbs of the genus Monarda

Other hypernyms of Monarda didyma include wild bergamot.

Monarda didyma (noun)	monarda (noun)
perennial aromatic herb of eastern North America having variously colored tubular flowers in dense showy heads	any of various aromatic herbs of the genus Monarda