plant organ vs plant structure

plant organ and plant structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
plant organ	Yes	No	No	No
plant structure	Yes	No	No	No

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

Other hypernyms of plant organ include plant part.

plant organ (noun)	plant structure (noun)
a functional and structural unit of a plant or fungus	any part of a plant or fungus