Eryngium maritimum vs shrub

Eryngium maritimum and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Eryngium maritimum	Yes	No	No	No
shrub	Yes	No	No	No

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

Eryngium maritimum: European evergreen eryngo with twisted spiny leaves naturalized on United States east coast; roots formerly used as an aphrodisiac
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Eryngium maritimum include bush.

Eryngium maritimum (noun)	shrub (noun)
European evergreen eryngo with twisted spiny leaves naturalized on United States east coast; roots formerly used as an aphrodisiac	a low woody perennial plant usually having several major stems