japanese clover vs bush clover

japanese clover and bush clover both are nouns.

Word	Noun	Adjective	Verb	Adverb
japanese clover	Yes	No	No	No
bush clover	Yes	No	No	No

As nouns, bush clover is a hypernym of japanese clover; that is, bush clover is a word with a broader meaning than japanese clover:

japanese clover: an annual of tropical Asia naturalized in United States
bush clover: shrubby or herbaceous plants widely used for forage, soil improvement, and especially hay in southern United States

Other hypernyms of japanese clover include lespedeza.

japanese clover (noun)	bush clover (noun)
an annual of tropical Asia naturalized in United States	shrubby or herbaceous plants widely used for forage, soil improvement, and especially hay in southern United States