helianthemum vs shrub

helianthemum and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
helianthemum	Yes	No	No	No
shrub	Yes	No	No	No

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

helianthemum: any plant of the genus Helianthemum; vigorous plants of stony alpine meadows and dry scrub regions
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of helianthemum include bush.

helianthemum (noun)	shrub (noun)
any plant of the genus Helianthemum; vigorous plants of stony alpine meadows and dry scrub regions	a low woody perennial plant usually having several major stems