plasmodium vs Plasmodium vivax

plasmodium and Plasmodium vivax both are nouns.

Word	Noun	Adjective	Verb	Adverb
plasmodium	Yes	No	No	No
Plasmodium vivax	Yes	No	No	No

As nouns, plasmodium and Plasmodium vivax are synonyms defined as:

plasmodium and Plasmodium vivax: parasitic protozoan of the genus Plasmodium that causes malaria in humans

Other synonyms of plasmodium include malaria parasite.

plasmodium (noun)	Plasmodium vivax (noun)
parasitic protozoan of the genus Plasmodium that causes malaria in humans	parasitic protozoan of the genus Plasmodium that causes malaria in humans
multinucleate sheet of cytoplasm characteristic of some stages of such organisms as slime molds