pakchoi vs cruciferous plant

pakchoi and cruciferous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
pakchoi	Yes	No	No	No
cruciferous plant	Yes	No	No	No

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

pakchoi: Asiatic plant grown for its cluster of edible white stalks with dark green leaves
cruciferous plant: any of various plants of the family Cruciferae

Other hypernyms of pakchoi include crucifer.

pakchoi (noun)	cruciferous plant (noun)
Asiatic plant grown for its cluster of edible white stalks with dark green leaves	any of various plants of the family Cruciferae