Alismales vs plant order

Alismales and plant order both are nouns.

Word	Noun	Adjective	Verb	Adverb
Alismales	Yes	No	No	No
plant order	Yes	No	No	No

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

Alismales (noun)	plant order (noun)
an order of aquatic monocotyledonous herbaceous plants	the order of plants