rice vs cultivated rice

rice and cultivated rice both are nouns.

Word	Noun	Adjective	Verb	Adverb
rice	Yes	No	Yes	No
cultivated rice	Yes	No	No	No

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

rice: annual or perennial rhizomatous marsh grasses; seed used for food; straw used for paper
cultivated rice: yields the staple food of 50 percent of world's population

Other hyponyms of rice include Oryza sativa.

rice (noun)	cultivated rice (noun)
grains used as food either unpolished or more often polished	yields the staple food of 50 percent of world's population
annual or perennial rhizomatous marsh grasses; seed used for food; straw used for paper

rice (verb)	cultivated rice (verb)
sieve so that it becomes the consistency of rice