twinflower vs subshrub

twinflower and subshrub both are nouns.

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

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

twinflower: creeping evergreen subshrub of the northern parts of Europe and Asia with delicate fragrant tubular bell-shaped usually pink flowers borne in pairs
subshrub: low-growing woody shrub or perennial with woody base

Other hypernyms of twinflower include suffrutex.

twinflower (noun)	subshrub (noun)
creeping evergreen subshrub of the northern parts of Europe and Asia with delicate fragrant tubular bell-shaped usually pink flowers borne in pairs	low-growing woody shrub or perennial with woody base