leaf beet vs common beet

leaf beet and common beet both are nouns.

Word	Noun	Adjective	Verb	Adverb
leaf beet	Yes	No	No	No
common beet	Yes	No	No	No

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

leaf beet: beet lacking swollen root; grown as a vegetable for its edible leaves and stalks
common beet: biennial Eurasian plant usually having a swollen edible root; widely cultivated as a food crop

Other hypernyms of leaf beet include beet, Beta vulgaris.

leaf beet (noun)	common beet (noun)
long succulent whitish stalks with large green leaves	biennial Eurasian plant usually having a swollen edible root; widely cultivated as a food crop
beet lacking swollen root; grown as a vegetable for its edible leaves and stalks