canna vs Canna indica

canna and Canna indica both are nouns.

Word	Noun	Adjective	Verb	Adverb
canna	Yes	No	No	No
Canna indica	Yes	No	No	No

As nouns, Canna indica is a hyponym of canna; that is, Canna indica is a word with a more specific, narrower meaning than canna:

canna: any plant of the genus Canna having large sheathing leaves and clusters of large showy flowers
Canna indica: canna grown especially for its edible rootstock from which arrowroot starch is obtained

Other hyponyms of canna include Canna generalis, canna lily, achira, arrowroot, Canna edulis, indian shot.

canna (noun)	Canna indica (noun)
any plant of the genus Canna having large sheathing leaves and clusters of large showy flowers	canna grown especially for its edible rootstock from which arrowroot starch is obtained