yam bean vs Pachyrhizus

yam bean and Pachyrhizus both are nouns.

Word	Noun	Adjective	Verb	Adverb
yam bean	Yes	No	No	No
Pachyrhizus	Yes	No	No	No

yam bean (noun)	Pachyrhizus (noun)
Central American twining plant with edible roots and pods; large tubers are eaten raw or cooked especially when young and young pods must be thoroughly cooked; pods and seeds also yield rotenone and oils	small genus of tropical vines having tuberous roots
twining plant of Amazon basin having large edible roots