sweet vetch vs subshrub

sweet vetch and subshrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet vetch	Yes	No	No	No
subshrub	Yes	No	No	No

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

sweet vetch: perennial of western United States having racemes of pink to purple flowers followed by flat pods that separate into nearly orbicular joints
subshrub: low-growing woody shrub or perennial with woody base

Other hypernyms of sweet vetch include suffrutex.

sweet vetch (noun)	subshrub (noun)
perennial of western United States having racemes of pink to purple flowers followed by flat pods that separate into nearly orbicular joints	low-growing woody shrub or perennial with woody base