air plant vs plant life

air plant and plant life both are nouns.

Word	Noun	Adjective	Verb	Adverb
air plant	Yes	No	No	No
plant life	Yes	No	No	No

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

air plant: plant that derives moisture and nutrients from the air and rain; usually grows on another plant but not parasitic on it
plant life: (botany) a living organism lacking the power of locomotion

Other hypernyms of air plant include flora, plant.

air plant (noun)	plant life (noun)
plant that derives moisture and nutrients from the air and rain; usually grows on another plant but not parasitic on it	(botany) a living organism lacking the power of locomotion