subshrub vs shrub

subshrub and shrub both are nouns.

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

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

Other hypernyms of subshrub include bush.

subshrub (noun)	shrub (noun)
low-growing woody shrub or perennial with woody base	a low woody perennial plant usually having several major stems