Pilea pumilla vs richweed

Pilea pumilla and richweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pilea pumilla	Yes	No	No	No
richweed	Yes	No	No	No

As nouns, Pilea pumilla and richweed are synonyms defined as:

Pilea pumilla and richweed: a plants of the genus Pilea having drooping green flower clusters and smooth translucent stems and leaves

Other synonyms of Pilea pumilla include clearweed, dead nettle.

Pilea pumilla (noun)	richweed (noun)
a plants of the genus Pilea having drooping green flower clusters and smooth translucent stems and leaves	a plants of the genus Pilea having drooping green flower clusters and smooth translucent stems and leaves
	erect perennial strong-scented with serrate pointed leaves and a loose panicle of yellowish flowers; the eastern United States