Oenothera vs dicot genus

Oenothera and dicot genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Oenothera	Yes	No	No	No
dicot genus	Yes	No	No	No

As nouns, dicot genus is a hypernym of Oenothera; that is, dicot genus is a word with a broader meaning than Oenothera:

Oenothera: chiefly North American herbs with usually nocturnal flowers
dicot genus: genus of flowering plants having two cotyledons (embryonic leaves) in the seed which usually appear at germination

Other hypernyms of Oenothera include magnoliopsid genus.

Oenothera (noun)	dicot genus (noun)
chiefly North American herbs with usually nocturnal flowers	genus of flowering plants having two cotyledons (embryonic leaves) in the seed which usually appear at germination