ephedra vs shrub

ephedra and shrub both are nouns.

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

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

ephedra: jointed and nearly leafless desert shrub having reduced scalelike leaves and reddish fleshy seeds
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of ephedra include bush.

ephedra (noun)	shrub (noun)
jointed and nearly leafless desert shrub having reduced scalelike leaves and reddish fleshy seeds	a low woody perennial plant usually having several major stems