rice vs Oryza sativa

rice and Oryza sativa both are nouns.

Word	Noun	Adjective	Verb	Adverb
rice	Yes	No	Yes	No
Oryza sativa	Yes	No	No	No

As nouns, Oryza sativa is a hyponym of rice; that is, Oryza sativa 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
Oryza sativa: yields the staple food of 50 percent of world's population

Other hyponyms of rice include cultivated rice.

rice (noun)	Oryza sativa (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)	Oryza sativa (verb)
sieve so that it becomes the consistency of rice