Diervilla sessilifolia vs shrub

Diervilla sessilifolia and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Diervilla sessilifolia	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of Diervilla sessilifolia; that is, shrub is a word with a broader meaning than Diervilla sessilifolia:

Diervilla sessilifolia: bush honeysuckle of southeastern United States having large crowded clusters of sulfur-yellow flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Diervilla sessilifolia include bush.

Diervilla sessilifolia (noun)	shrub (noun)
bush honeysuckle of southeastern United States having large crowded clusters of sulfur-yellow flowers	a low woody perennial plant usually having several major stems