columnea vs shrub

columnea and shrub both are nouns.

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

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

columnea: tropical plant having thick hairy somewhat toothed leaves and solitary or clustered yellow to scarlet flowers; many cultivated for their flowers and ornamental foliage
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of columnea include bush.

columnea (noun)	shrub (noun)
tropical plant having thick hairy somewhat toothed leaves and solitary or clustered yellow to scarlet flowers; many cultivated for their flowers and ornamental foliage	a low woody perennial plant usually having several major stems