Ulex europaeus vs shrub

Ulex europaeus and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ulex europaeus	Yes	No	No	No
shrub	Yes	No	No	No

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

Ulex europaeus: very spiny and dense evergreen shrub with fragrant golden-yellow flowers; common throughout western Europe
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Ulex europaeus include bush.

Ulex europaeus (noun)	shrub (noun)
very spiny and dense evergreen shrub with fragrant golden-yellow flowers; common throughout western Europe	a low woody perennial plant usually having several major stems