chlamys vs plant organ

chlamys and plant organ both are nouns.

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

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

chlamys: collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils
plant organ: a functional and structural unit of a plant or fungus

Other hypernyms of chlamys include cover, covering, natural covering.

chlamys (noun)	plant organ (noun)
a short mantle or cape fastened at the shoulder; worn by men in ancient Greece	a functional and structural unit of a plant or fungus
collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils