Knowlton's cactus vs Pediocactus knowltonii

Knowlton's cactus and Pediocactus knowltonii both are nouns.

Word	Noun	Adjective	Verb	Adverb
Knowlton's cactus	Yes	No	No	No
Pediocactus knowltonii	Yes	No	No	No

As nouns, Knowlton's cactus and Pediocactus knowltonii are synonyms defined as:

Knowlton's cactus and Pediocactus knowltonii: small clustering cactus of southwestern United States; a threatened species

Knowlton's cactus (noun)	Pediocactus knowltonii (noun)
small clustering cactus of southwestern United States; a threatened species	small clustering cactus of southwestern United States; a threatened species