dwarf elder vs subshrub

dwarf elder and subshrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
dwarf elder	Yes	No	No	No
subshrub	Yes	No	No	No

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

dwarf elder: bristly herb of eastern and central North America having black fruit and medicinal bark
subshrub: low-growing woody shrub or perennial with woody base

Other hypernyms of dwarf elder include suffrutex.

dwarf elder (noun)	subshrub (noun)
dwarf herbaceous elder of Europe having pink flowers and a nauseous odor	low-growing woody shrub or perennial with woody base
bristly herb of eastern and central North America having black fruit and medicinal bark