coca plant vs shrub

coca plant and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
coca plant	Yes	No	No	No
shrub	Yes	No	No	No

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

coca plant: a South American shrub whose leaves are chewed by natives of the Andes; a source of cocaine
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of coca plant include bush.

coca plant (noun)	shrub (noun)
a South American shrub whose leaves are chewed by natives of the Andes; a source of cocaine	a low woody perennial plant usually having several major stems