cattail vs bog plant

cattail and bog plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
cattail	Yes	No	No	No
bog plant	Yes	No	No	No

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

cattail: tall erect herbs with sword-shaped leaves; cosmopolitan in fresh and salt marshes
bog plant: a semiaquatic plant that grows in soft wet land; most are monocots: sedge, sphagnum, grasses, cattails, etc; possibly heath

Other hypernyms of cattail include marsh plant, swamp plant.

cattail (noun)	bog plant (noun)
tall erect herbs with sword-shaped leaves; cosmopolitan in fresh and salt marshes	a semiaquatic plant that grows in soft wet land; most are monocots: sedge, sphagnum, grasses, cattails, etc; possibly heath