order Rosales vs plant order

order Rosales and plant order both are nouns.

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

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

order Rosales: in some classifications this category does not include Leguminosae
plant order: the order of plants

order Rosales (noun)	plant order (noun)
in some classifications this category does not include Leguminosae	the order of plants