bush clover vs ligneous plant

bush clover and ligneous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
bush clover	Yes	No	No	No
ligneous plant	Yes	No	No	No

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

bush clover: shrubby or herbaceous plants widely used for forage, soil improvement, and especially hay in southern United States
ligneous plant: a plant having hard lignified tissues or woody parts especially stems

Other hypernyms of bush clover include woody plant.

bush clover (noun)	ligneous plant (noun)
shrubby or herbaceous plants widely used for forage, soil improvement, and especially hay in southern United States	a plant having hard lignified tissues or woody parts especially stems