bok choi vs crucifer

bok choi and crucifer both are nouns.

Word	Noun	Adjective	Verb	Adverb
bok choi	Yes	No	No	No
crucifer	Yes	No	No	No

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

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

Other hypernyms of bok choi include cruciferous plant.

bok choi (noun)	crucifer (noun)
elongated head of dark green leaves on thick white stalks	any of various plants of the family Cruciferae
Asiatic plant grown for its cluster of edible white stalks with dark green leaves