fireweed vs Erechtites hieracifolia

fireweed and Erechtites hieracifolia both are nouns.

Word	Noun	Adjective	Verb	Adverb
fireweed	Yes	No	No	No
Erechtites hieracifolia	Yes	No	No	No

As nouns, fireweed and Erechtites hieracifolia are synonyms defined as:

fireweed and Erechtites hieracifolia: an American weedy plant with small white or greenish flowers

fireweed (noun)	Erechtites hieracifolia (noun)
tall North American perennial with creeping rootstocks and narrow leaves and spikes of pinkish-purple flowers occurring in great abundance in burned-over areas or recent clearings; an important honey plant	an American weedy plant with small white or greenish flowers
an American weedy plant with small white or greenish flowers