digitalis vs digitoxin

digitalis and digitoxin both are nouns.

Word	Noun	Adjective	Verb	Adverb
digitalis	Yes	No	No	No
digitoxin	Yes	No	No	No

As nouns, digitoxin is a hyponym of digitalis; that is, digitoxin is a word with a more specific, narrower meaning than digitalis:

digitalis: a powerful cardiac stimulant obtained from foxglove
digitoxin: digitalis preparation used to treat congestive heart failure or cardiac arrhythmia

Other hyponyms of digitalis include digoxin, Lanoxin.

digitalis (noun)	digitoxin (noun)
any of several plants of the genus Digitalis	digitalis preparation used to treat congestive heart failure or cardiac arrhythmia
a powerful cardiac stimulant obtained from foxglove