cress plant vs crucifer

cress plant and crucifer both are nouns.

Word	Noun	Adjective	Verb	Adverb
cress plant	Yes	No	No	No
crucifer	Yes	No	No	No

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

cress plant: any of various plants of the family Cruciferae with edible leaves that have a pungent taste
crucifer: any of various plants of the family Cruciferae

Other hypernyms of cress plant include cruciferous plant.

cress plant (noun)	crucifer (noun)
any of various plants of the family Cruciferae with edible leaves that have a pungent taste	any of various plants of the family Cruciferae