Kiggelaria africana vs shrub

Kiggelaria africana and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Kiggelaria africana	Yes	No	No	No
shrub	Yes	No	No	No

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

Kiggelaria africana: large much-branched shrub grown primarily for its evergreen foliage
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Kiggelaria africana include bush.

Kiggelaria africana (noun)	shrub (noun)
large much-branched shrub grown primarily for its evergreen foliage	a low woody perennial plant usually having several major stems