lupin vs ligneous plant

lupin and ligneous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
lupin	Yes	No	No	No
ligneous plant	Yes	No	No	No

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

lupin: any plant of the genus Lupinus; bearing erect spikes of usually purplish-blue flowers
ligneous plant: a plant having hard lignified tissues or woody parts especially stems

Other hypernyms of lupin include woody plant.

lupin (noun)	ligneous plant (noun)
any plant of the genus Lupinus; bearing erect spikes of usually purplish-blue flowers	a plant having hard lignified tissues or woody parts especially stems