lithophytic plant vs rock plant

lithophytic plant and rock plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
lithophytic plant	Yes	No	No	No
rock plant	Yes	No	No	No

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

lithophytic plant: plant that grows on rocks or stony soil and derives nourishment from the atmosphere
rock plant: plant that grows on or among rocks or is suitable for a rock garden

lithophytic plant (noun)	rock plant (noun)
plant that grows on rocks or stony soil and derives nourishment from the atmosphere	plant that grows on or among rocks or is suitable for a rock garden