rubiaceous plant vs angiosperm

rubiaceous plant and angiosperm both are nouns.

Word	Noun	Adjective	Verb	Adverb
rubiaceous plant	Yes	No	No	No
angiosperm	Yes	No	No	No

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

rubiaceous plant: any of numerous trees or shrubs or vines of the family Rubiaceae
angiosperm: plants having seeds in a closed ovary

Other hypernyms of rubiaceous plant include flowering plant.

rubiaceous plant (noun)	angiosperm (noun)
any of numerous trees or shrubs or vines of the family Rubiaceae	plants having seeds in a closed ovary