common sorrel vs greens

common sorrel and greens both are nouns.

Word	Noun	Adjective	Verb	Adverb
common sorrel	Yes	No	No	No
greens	Yes	No	No	No

As nouns, greens is a hypernym of common sorrel; that is, greens is a word with a broader meaning than common sorrel:

common sorrel: large sour-tasting arrowhead-shaped leaves used in salads and sauces
greens: any of various leafy plants or their leaves and stems eaten as vegetables

Other hypernyms of common sorrel include green, leafy vegetable.

common sorrel (noun)	greens (noun)
large sour-tasting arrowhead-shaped leaves used in salads and sauces	any of various leafy plants or their leaves and stems eaten as vegetables