Euonymus americanus vs shrub

Euonymus americanus and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Euonymus americanus	Yes	No	No	No
shrub	Yes	No	No	No

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

Euonymus americanus: upright deciduous plant with crimson pods and seeds; the eastern United States from New York to Florida and Texas
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Euonymus americanus include bush.

Euonymus americanus (noun)	shrub (noun)
upright deciduous plant with crimson pods and seeds; the eastern United States from New York to Florida and Texas	a low woody perennial plant usually having several major stems