Apocynum pumilum vs Rocky Mountain dogbane

Apocynum pumilum and Rocky Mountain dogbane both are nouns.

Word	Noun	Adjective	Verb	Adverb
Apocynum pumilum	Yes	No	No	No
Rocky Mountain dogbane	Yes	No	No	No

As nouns, Apocynum pumilum and Rocky Mountain dogbane are synonyms defined as:

Apocynum pumilum and Rocky Mountain dogbane: North American plant similar to common dogbane

Apocynum pumilum (noun)	Rocky Mountain dogbane (noun)
North American plant similar to common dogbane	North American plant similar to common dogbane