order Rubiales vs plant order

order Rubiales and plant order both are nouns.

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

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

order Rubiales: an order of dicotyledonous plants of the subclass Asteridae; have opposite leaves and an inferior compound ovary
plant order: the order of plants

order Rubiales (noun)	plant order (noun)
an order of dicotyledonous plants of the subclass Asteridae; have opposite leaves and an inferior compound ovary	the order of plants