rock geranium vs alumroot

rock geranium and alumroot both are nouns.

Word	Noun	Adjective	Verb	Adverb
rock geranium	Yes	No	No	No
alumroot	Yes	No	No	No

As nouns, alumroot is a hypernym of rock geranium; that is, alumroot is a word with a broader meaning than rock geranium:

rock geranium: plant with basal leaves mottled with white and flowers in lax panicles on erect stems
alumroot: any of several herbs of the genus Heuchera

Other hypernyms of rock geranium include alumbloom.

rock geranium (noun)	alumroot (noun)
plant with basal leaves mottled with white and flowers in lax panicles on erect stems	any of several herbs of the genus Heuchera