perennial ragweed vs Ambrosia psilostachya

perennial ragweed and Ambrosia psilostachya both are nouns.

Word	Noun	Adjective	Verb	Adverb
perennial ragweed	Yes	No	No	No
Ambrosia psilostachya	Yes	No	No	No

As nouns, perennial ragweed and Ambrosia psilostachya are synonyms defined as:

perennial ragweed and Ambrosia psilostachya: coarse perennial ragweed with creeping roots of dry barren lands of southwestern United States and Mexico

Other synonyms of perennial ragweed include western ragweed.

perennial ragweed (noun)	Ambrosia psilostachya (noun)
coarse perennial ragweed with creeping roots of dry barren lands of southwestern United States and Mexico	coarse perennial ragweed with creeping roots of dry barren lands of southwestern United States and Mexico