calla vs flower

calla and flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
calla	Yes	No	No	No
flower	Yes	No	Yes	No

As nouns, flower is a hypernym of calla; that is, flower is a word with a broader meaning than calla:

calla: South African plant widely cultivated for its showy pure white spathe and yellow spadix
flower: a plant cultivated for its blooms or blossoms

calla (noun)	flower (noun)
South African plant widely cultivated for its showy pure white spathe and yellow spadix	a plant cultivated for its blooms or blossoms
	reproductive organ of angiosperm plants especially one having showy or colorful parts
	the period of greatest prosperity or productivity

calla (verb)	flower (verb)
	produce or yield flowers