hoary pea vs subshrub

hoary pea and subshrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
hoary pea	Yes	No	No	No
subshrub	Yes	No	No	No

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

hoary pea: a plant of the genus Tephrosia having pinnate leaves and white or purplish flowers and flat hairy pods
subshrub: low-growing woody shrub or perennial with woody base

Other hypernyms of hoary pea include suffrutex.

hoary pea (noun)	subshrub (noun)
a plant of the genus Tephrosia having pinnate leaves and white or purplish flowers and flat hairy pods	low-growing woody shrub or perennial with woody base